simplify the cache keys

Author: erik-krogh

.github/workflows/compile-queries.yml

@@ -29,17 +29,17 @@ jobs:
           path: '*/ql/src/.cache'
           key: codeql-compile-pr-${{ github.sha }} # deliberately not using the `compile-compile-main` keys here.
           restore-keys: |
-            codeql-compile-refs/heads/${{ github.base_ref }}-${{ env.merge-base }}
-            codeql-compile-refs/heads/${{ github.base_ref }}-
+            codeql-compile-${{ github.base_ref }}-${{ env.merge-base }}
+            codeql-compile-${{ github.base_ref }}-
       - name: Fill CodeQL query compilation cache - main
         if: ${{ github.event_name != 'pull_request' }}
         uses: actions/cache@v3
         with:
           path: '*/ql/src/.cache'
-          key: codeql-compile-${{ github.ref }}-${{ github.sha }} # just fill on main
+          key: codeql-compile-${{ github.ref_name }}-${{ github.sha }} # just fill on main
           restore-keys: | # restore from another random commit, to speed up compilation.
-            codeql-compile-${{ github.ref }}- 
-            codeql-compile-refs/heads/main-
+            codeql-compile-${{ github.ref_name }}- 
+            codeql-compile-main-
       - name: Setup CodeQL
         uses: ./.github/actions/fetch-codeql
         with: