Fix ref syntax

Author: NullVoxPopuli

.github/workflows/package-size.yml

@@ -16,7 +16,7 @@ jobs:
     steps:
       - uses: actions/checkout@v6
       - uses: ./.github/actions/setup
-      - uses: wyvox/pkg-size#copilot/add-ignore-diffs-option
+      - uses: wyvox/pkg-size@copilot/add-ignore-diffs-option
         with:
           build-command: "pnpm build"
           display-size: uncompressed, brotli