github: Remove commit ID from cache keys

This reduces the cache storage for active branches and since caches for
different branches are separate and we abort previous builds of the same
branch, this is not necessary to ensure caches can successfully be stored.

.github/workflows/macos.yml

@@ -39,9 +39,7 @@ jobs:
       - uses: actions/cache@v5
         with:
           path: ~/Library/Caches/ccache
-          key: ccache-${{ runner.os }}-${{ github.sha }}
-          restore-keys: |
-            ccache-${{ runner.os }}-
+          key: ccache-${{ runner.os }}
       # workaround for conflict between Python installed in the image and via brew
       - run: find /usr/local/bin -lname '*/Library/Frameworks/Python.framework/*' -delete -print
       - run: |