Use mithro/docker-metadata-action.

Use my custom hacked version of docker-metadata-action until
https://github.com/docker/metadata-action/issues/90 is fixed in the
upstream repository.

Signed-off-by: Tim 'mithro' Ansell <tansell@google.com>

.github/workflows/build-docker-image-run-drc-for-cell-gds-using-magic.yml

diff --git a/.github/workflows/build-docker-image-run-drc-for-cell-gds-using-magic.yml b/.github/workflows/build-docker-image-run-drc-for-cell-gds-using-magic.yml
index 6b9a8f1..62a48b5 100644
--- a/.github/workflows/build-docker-image-run-drc-for-cell-gds-using-magic.yml
+++ b/.github/workflows/build-docker-image-run-drc-for-cell-gds-using-magic.yml
@@ -108,7 +108,7 @@
 
     - name: Docker meta
       id: docker_meta
-      uses: docker/metadata-action@v3
+      uses: mithro/docker-metadata-action@master
       with:
         images: ${{ steps.push_to.outputs.images }}
         tags: |