chore(ci): fix source directory

.github/workflows/ci.yml

@@ -38,7 +38,7 @@ jobs:
           # The Git commit id of vcpkg to be checked out. This is only needed because we are not using a submodule.
           vcpkgGitCommitId: '3508985146f1b1d248c67ead13f8f54be5b4f5da'
           # The vcpkg.json file, which will be part of cache key computation.
-          vcpkgJsonGlob: '${{ runner.workspace }}/vcpkg.json'
+          vcpkgJsonGlob: '${{ github.workspace }}/vcpkg.json'
 
       - name: Prints output of run-vcpkg's action
         run: echo "root='${{ steps.runvcpkg.outputs.RUNVCPKG_VCPKG_ROOT_OUT }}', triplet='${{ steps.runvcpkg.outputs.RUNVCPKG_VCPKG_DEFAULT_TRIPLET_OUT }}'"