Bump azure/docker-login from 1 to 2 in /.github/actions/backend-deploy

Bumps [azure/docker-login](https://github.com/azure/docker-login) from 1 to 2.
- [Release notes](https://github.com/azure/docker-login/releases)
- [Commits](Azure/docker-login@v1...v2)

---
updated-dependencies:
- dependency-name: azure/docker-login
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

.github/actions/backend-deploy/action.yml

@@ -43,7 +43,7 @@ runs:
     #     creds: ${{ env.AZURE_CREDENTIALS }}
 
     - name: "Docker Login"
-      uses: azure/docker-login@v1
+      uses: azure/docker-login@v2
       with:
         login-server: ${{ env.DOCKER_REGISTRY_SERVER }}
         username: ${{ env.DOCKER_REGISTRY_USERNAME }}