fix: use update-container-description-action instead of raw docker-pushrm

The raw docker run with docker-pushrm keeps failing due to WORKDIR /
mount path mismatches. Replace with the official GitHub Action wrapper
from the same author, which handles the internals correctly.

.gitea/workflows/build-and-deploy.yml

@@ -76,10 +76,11 @@ jobs:
             ${{ steps.meta.outputs.tag_latest }}
 
       - name: Push README to Docker Hub
-        run: >
-          docker run --rm
-          -v "$(pwd)/README.md:/README.md:ro"
-          -e DOCKER_USER="${{ vars.DOCKER_HUB_USERNAME }}"
-          -e DOCKER_PASS="${{ secrets.DOCKER_HUB_TOKEN }}"
-          chko/docker-pushrm:latest
-          "${{ vars.DOCKER_HUB_USERNAME }}/${{ env.APP_NAME }}"
+        uses: christian-korneck/update-container-description-action@v1
+        env:
+          DOCKER_USER: ${{ vars.DOCKER_HUB_USERNAME }}
+          DOCKER_PASS: ${{ secrets.DOCKER_HUB_TOKEN }}
+        with:
+          destination_container_repo: ${{ vars.DOCKER_HUB_USERNAME }}/${{ env.APP_NAME }}
+          provider: dockerhub
+          readme_file: README.md