dev: reduce docker layers & combine install commands

Dockerfile

@@ -54,9 +54,7 @@ RUN apt-get update && apt-get install -y \
     lib32z1 \
     libusb-1.0-0-dev \
     libudev-dev \
-    libhidapi-dev
-
-RUN apt-get update && apt-get install -y \
+    libhidapi-dev \
     doxygen \
     graphviz
 
@@ -75,22 +73,20 @@ RUN python3 -m pip install --upgrade pip
 
 # Python modules
 COPY py/bitbox02 /tmp/bitbox02
-RUN python3 -m pip install /tmp/bitbox02
-RUN rm -r /tmp/bitbox02
+RUN python3 -m pip install /tmp/bitbox02 && \
+    rm -r /tmp/bitbox02
 COPY py/requirements.txt /tmp
-RUN python3 -m pip install --upgrade --requirement /tmp/requirements.txt
-RUN rm /tmp/requirements.txt
+RUN python3 -m pip install --upgrade --requirement /tmp/requirements.txt && \
+    rm /tmp/requirements.txt
 
-# Python modules for CI
 RUN python3 -m pip install --upgrade \
+    # Python modules for CI
     pylint==2.13.9 \
     pylint-protobuf==0.20.2 \
     black==22.3.0 \
     mypy==0.960 \
-    mypy-protobuf==3.2.0
-
-# Python modules for packaging
-RUN python3 -m pip install --upgrade \
+    mypy-protobuf==3.2.0 \
+    # Python modules for packaging
     setuptools==41.2.0 \
     wheel==0.33.6 \
     twine==1.15.0
@@ -104,16 +100,13 @@ ENV PATH /opt/protoc/bin:$PATH
 # Make Python3 the default
 RUN update-alternatives --install /usr/bin/python python /usr/bin/python3 1
 
-# Developer tools
-RUN apt-get update && apt-get install -y \
-    bash-completion
 # Install gcovr from PIP to get a newer version than in apt repositories
 RUN python3 -m pip install gcovr
 
 # Install Go, used for the tools in tools/go and for test/gounittest
-ENV GOPATH /opt/go
-ENV GOROOT /opt/go_dist/go
-ENV PATH $GOROOT/bin:$GOPATH/bin:$PATH
+ENV GOPATH=/opt/go \
+    GOROOT=/opt/go_dist/go \
+    PATH=$GOROOT/bin:$GOPATH/bin:$PATH
 RUN mkdir -p /opt/go_dist && \
     curl https://dl.google.com/go/go1.19.3.linux-amd64.tar.gz | tar -xz -C /opt/go_dist
 
@@ -122,8 +115,8 @@ RUN cd /opt && wget https://github.com/linux-test-project/lcov/releases/download
 ENV PATH /opt/lcov-1.14/bin:$PATH
 
 # Install rust compiler
-ENV PATH /opt/cargo/bin:$PATH
-ENV RUSTUP_HOME=/opt/rustup
+ENV PATH=/opt/cargo/bin:$PATH \
+    RUSTUP_HOME=/opt/rustup
 COPY src/rust/rust-toolchain /tmp/rust-toolchain
 RUN curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | CARGO_HOME=/opt/cargo sh -s -- --default-toolchain $(cat /tmp/rust-toolchain | tr -d '\r\n\t') -y
 RUN rustup target add thumbv7em-none-eabi