fix: grep repo path

Signed-off-by: Zhanhui Li <[email protected]>

.github/workflows/cpp_tagged_release.yaml

@@ -21,7 +21,7 @@ jobs:
           # Otherwise, uses the default branch.
           ref: 'v1.46.3'
           # Relative path under $GITHUB_WORKSPACE to place the repository
-          path: repo/grpc
+          path: cpp/repo/grpc
           submodules: true
       - name: "Install Dependencies"
         run: |