Vcpkg cache artifacts on macOS

Author: MathiasMagnus

.github/workflows/macos.yml

@@ -188,6 +188,16 @@ jobs:
             popd
           fi
 
+      - name: Export GitHub Actions cache and vcpkg environment variables
+        if: matrix.options.loadtests != 'OFF'
+        uses: actions/github-script@v7
+        with:
+          # Caution. JSON in use. "#core" breaks the build.
+          script: |
+            core.exportVariable('ACTIONS_CACHE_URL', process.env.ACTIONS_CACHE_URL || '');
+            core.exportVariable('ACTIONS_RUNTIME_TOKEN', process.env.ACTIONS_RUNTIME_TOKEN || '');
+            core.exportVariable('VCPKG_BINARY_SOURCES', "clear;x-gha,readwrite");
+
       - name: Install Doxygen
         if: matrix.options.doc == 'ON'
         uses: ssciwr/doxygen-install@v1