Remove x86 MacOS jobs and use M1 instead (#8446)

.github/scripts/setup-env.sh

@@ -22,17 +22,6 @@ case $(uname) in
     ;;
 esac
 
-if [[ "${OS_TYPE}" == "macos" && $(uname -m) == x86_64 ]]; then
-  echo '::group::Uninstall system JPEG libraries on macOS'
-  # The x86 macOS runners, e.g. the GitHub Actions native "macos-12" runner, has some JPEG and PNG libraries
-  # installed by default that interfere with our build. We uninstall them here and use the one from conda below.
-  IMAGE_LIBS=$(brew list | grep -E "jpeg|png")
-  for lib in $IMAGE_LIBS; do
-    brew uninstall --ignore-dependencies --force "${lib}"
-  done
-  echo '::endgroup::'
-fi
-
 echo '::group::Create build environment'
 # See https://github.com/pytorch/vision/issues/7296 for ffmpeg
 conda create \

.github/workflows/build-cmake.yml

@@ -40,7 +40,6 @@ jobs:
     strategy:
       matrix:
         include:
-          - runner: macos-12
           - runner: macos-m1-stable
       fail-fast: false
     uses: pytorch/test-infra/.github/workflows/macos_job.yml@main

.github/workflows/tests.yml

@@ -53,16 +53,11 @@ jobs:
           - "3.10"
           - "3.11"
           - "3.12"
-        runner: ["macos-12"]
-        include:
-          - python-version: "3.8"
-            runner: macos-m1-stable
+        runner: ["macos-m1-stable"]
       fail-fast: false
     uses: pytorch/test-infra/.github/workflows/macos_job.yml@main
     with:
       repository: pytorch/vision
-      # We need an increased timeout here, since the macos-12 runner is the free one from GH
-      # and needs roughly 2 hours to just run the test suite
       timeout: 240
       runner: ${{ matrix.runner }}
       test-infra-ref: main