CI: Cache macOS Homebrew and Scons (#788)

* CI: Cache macOS builds

* try caching now

* close

* revert

* save homebrew cache

* final

.github/workflows/selfdrive_tests.yaml

@@ -105,6 +105,12 @@ jobs:
       env:
         # package install has DeprecationWarnings
         PYTHONWARNINGS: default
+    - name: Save Homebrew cache
+      uses: actions/cache/save@v4
+      if: (github.ref == 'refs/heads/master' || github.ref == 'refs/heads/master-new')
+      with:
+        path: ~/Library/Caches/Homebrew
+        key: brew-macos-${{ env.CACHE_COMMIT_DATE }}-${{ github.sha }}
     - run: git lfs pull
     - name: Getting scons cache
       uses: ./.github/workflows/auto-cache
@@ -116,6 +122,12 @@ jobs:
           scons-${{ runner.arch }}-macos
     - name: Building openpilot
       run: . .venv/bin/activate && scons -j$(nproc)
+    - name: Save scons cache
+      uses: actions/cache/save@v4
+      if: (github.ref == 'refs/heads/master' || github.ref == 'refs/heads/master-new')
+      with:
+        path: /tmp/scons_cache
+        key: scons-${{ runner.arch }}-macos-${{ env.CACHE_COMMIT_DATE }}-${{ github.sha }}
 
   static_analysis:
     name: static analysis