Update lucacome/docker-image-update-checker action to v3 (#303)

| datasource  | package                              | from   | to     |
| ----------- | ------------------------------------ | ------ | ------ |
| github-tags | lucacome/docker-image-update-checker | v2.0.0 | v3.0.0 |

Signed-off-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/update-docker-images.yml

@@ -34,7 +34,7 @@ jobs:
     steps:
       - name: Check if update available
         id: update
-        uses: lucacome/docker-image-update-checker@a233de0585661c019fb71f9601328db37051cc66 # v2.0.0
+        uses: lucacome/docker-image-update-checker@5d84572804be8bd4dc353f08c8437efdb6af37ac # v3.0.0
         with:
           base-image: ${{ needs.variables.outputs.ubi_version }}
           image: nginxcontrib/nginx-ubi:${{ needs.variables.outputs.nginx_version }}