chore(github-action): update github action to not use self-hosted runner

.github/workflows/build-and-deploy.yaml

@@ -5,14 +5,16 @@ on:  # yamllint disable-line rule:truthy
   push:
 jobs:
   build:
-    runs-on: self-hosted 
-    # runs-on: ubuntu-latest
+    # when running on self-hosted, uncomment the following and comment out the subsequent line 
+    # runs-on: self-hosted 
+    runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
         with:
           fetch-depth: 0
-      # - uses: DeterminateSystems/nix-installer-action@main
-      # - uses: DeterminateSystems/magic-nix-cache-action@main
+      # when running on a self-hosted nixos system, I removed the following 2 uses...
+      - uses: DeterminateSystems/nix-installer-action@main
+      - uses: DeterminateSystems/magic-nix-cache-action@main
       - run: |
           scripts/build_and_push_image.sh
         env: