Drop support for the RPI buster

And remove some comments that are not relevant anymore

.github/workflows/main.yml

@@ -136,12 +136,8 @@ jobs:
     needs: build-docstrings
     strategy:
       matrix:
-        rpi-os: [rpi-buster, rpi-bullseye, rpi-bookworm]
+        rpi-os: [rpi-bullseye, rpi-bookworm]
     runs-on: ${{ matrix.rpi-os }}
-    env:
-      # workaround required for cache@v3, https://github.com/actions/cache/issues/1428
-      # to be removed when upgrading the manylinux image
-      ACTIONS_ALLOW_USE_UNSECURE_NODE_VERSION: true
     steps:
       - name: Print home directory
         run: echo Home directory inside container $HOME
@@ -304,10 +300,6 @@ jobs:
   build-linux-x86_64:
     needs: build-docstrings
     runs-on: ubuntu-latest
-    env:
-      # workaround required for cache@v3, https://github.com/actions/cache/issues/1428
-      # to be removed when upgrading the manylinux image
-      ACTIONS_ALLOW_USE_UNSECURE_NODE_VERSION: true
     container:
       image: quay.io/pypa/manylinux_2_28_x86_64:latest
       env:
@@ -372,10 +364,6 @@ jobs:
   build-linux-arm64:
     needs: build-docstrings
     runs-on: [self-hosted, linux, ARM64]
-    env:
-      # workaround required for cache@v3, https://github.com/actions/cache/issues/1428
-      # to be removed when upgrading the manylinux image
-      ACTIONS_ALLOW_USE_UNSECURE_NODE_VERSION: true
     container:
       image: quay.io/pypa/manylinux_2_28_aarch64:latest
       env: