What does this PR do?

Currently building on aarch64 CPU fails with the following error:

/usr/local/cargo/registry/src/index.crates.io-6f17d22bba15001f/luajit-src-210.5.3+29b0b28/luajit2/src/lj_mcode.c

  = note: /usr/lib/gcc/aarch64-alpine-linux-musl/13.2.1/../../../../aarch64-alpine-linux-musl/bin/ld: /tmp/rustcesPkLe/libmlua_sys-1c0e60c0a5d4bc62.rlib(lj_mcode.o): in function `lj_mcode_sync':
          lj_mcode.c:(.text.lj_mcode_sync+0x4): undefined reference to `__clear_cache'
          collect2: error: ld returned 1 exit status

This PR fixes that issue.

Why is this change important?

This change will allow us to run websurfx on devices with ARM64 CPU like Raspberry Pi.

How to test this PR locally?

1. Log in to an ARM64-based machine, such as a Raspberry Pi, a MacBook with Apple silicon, or spin up a virtual machine (VM) with ARM64 on any cloud provider that offers such services.
2. Checkout the branch
3. Build a new container image

   docker build -t websurfx --platform=linux/aarch64 .
   
   [+] Building 262.2s (20/20) FINISHED                                                                                                                          docker:orbstack
    => [internal] load build definition from Dockerfile                                                                                                                     0.0s
    => => transferring dockerfile: 2.44kB                                                                                                                                   0.0s
    => [internal] load .dockerignore                                                                                                                                        0.0s
    => => transferring context: 127B                                                                                                                                        0.0s
    => [internal] load metadata for docker.io/library/rust:1.75.0-alpine3.18                                                                                                0.0s
    => [chef 1/4] FROM docker.io/library/rust:1.75.0-alpine3.18                                                                                                             0.0s
    => [internal] load build context                                                                                                                                        0.0s
    => => transferring context: 4.92kB                                                                                                                                      0.0s
    => CACHED [chef 2/4] RUN apk add --no-cache alpine-sdk musl-dev g++ make libcrypto3 libressl-dev upx perl build-base                                                    0.0s
    => CACHED [chef 3/4] RUN cargo install cargo-chef --locked                                                                                                              0.0s
    => CACHED [chef 4/4] WORKDIR /app                                                                                                                                       0.0s
    => CACHED [planner 1/3] COPY ./Cargo.toml ./Cargo.lock ./                                                                                                               0.0s
    => [planner 2/3] COPY .cargo/config ./.cargo/config                                                                                                                     0.0s
    => [planner 3/3] RUN cargo chef prepare --recipe-path recipe.json                                                                                                       0.2s
    => [builder 1/6] COPY --from=planner /app/recipe.json recipe.json                                                                                                       0.0s
    => [builder 2/6] RUN export ARCH=$(uname -m) &&   if [ "memory" = "memory" ] ; then cargo chef cook --release --target=$ARCH-unknown-linux-musl --recipe-path recipe  120.8s
    => [builder 3/6] COPY ./src ./src                                                                                                                                       0.0s
    => [builder 4/6] COPY ./public ./public                                                                                                                                 0.0s
    => [builder 5/6] RUN export ARCH=$(uname -m) &&   if [ "memory" = "memory" ] ; then cargo build --release --target=$ARCH-unknown-linux-musl ;   else if [ "memory" =  131.3s
    => [builder 6/6] RUN export ARCH=$(uname -m)   && upx --lzma --best /app/target/$ARCH-unknown-linux-musl/release/websurfx   && cp /app/target/$ARCH-unknown-linux-musl  9.5s
    => [stage-3 1/2] COPY --from=builder /app/public/ /opt/websurfx/public/                                                                                                 0.0s
    => [stage-3 2/2] COPY --from=builder /usr/local/bin/websurfx /usr/local/bin/websurfx                                                                                    0.0s
    => exporting to image                                                                                                                                                   0.0s
    => => exporting layers                                                                                                                                                  0.0s
    => => writing image sha256:3afc96a22e907d9fa1b800c5b7e96244e60e4f2ab94e10a813caf1155f774700                                                                             0.0s
    => => naming to docker.io/library/websurfx                                                                                                                              0.0s

4. Run a container from the image

   docker run -t --platform=linux/aarch64 -v ./websurfx/config.lua:/etc/xdg/websurfx/config.lua websurfx
   [INFO  websurfx::cache::cacher] Initialising in-memory cache
   [INFO  websurfx] started server on port 8080 and IP 127.0.0.1
   [INFO  websurfx] Open http://127.0.0.1:8080/ in your browser
   [INFO  actix_server::builder] starting 10 workers
   [INFO  actix_server::server] Actix runtime found; starting in Actix runtime

Author's checklist

Here a user explains about the same linking problem and how he has fixed it.
So, all the credits should go to him.
I only adjusted the .cargo/config for this specific project and tested the solution.

Related issues

Closes #505