[ci] Bump docker/login-action from 3 to 4

Bumps [docker/login-action](https://github.com/docker/login-action) from 3 to 4.
- [Release notes](https://github.com/docker/login-action/releases)
- [Commits](docker/login-action@v3...v4)

---
updated-dependencies:
- dependency-name: docker/login-action
  dependency-version: '4'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -90,7 +90,7 @@ jobs:
       # echo "$DOCKER_HUB_SECRET" | docker login --username "$DOCKER_HUB_USERNAME" --password-stdin
       - name: Login to Docker Hub
         if: ${{ success() && github.event_name == 'push' && github.ref == 'refs/heads/master' }}
-        uses: docker/login-action@v3
+        uses: docker/login-action@v4
         with:
           username: ${{ secrets.DOCKER_HUB_USERNAME }}
           password: ${{ secrets.DOCKER_HUB_SECRET }}
@@ -105,7 +105,7 @@ jobs:
 
       - name: Login to GitLab Container Registry
         if: ${{ success() && github.event_name == 'push' && github.ref == 'refs/heads/master' }}
-        uses: docker/login-action@v3
+        uses: docker/login-action@v4
         with:
           registry: registry.gitlab.com
           username: ${{ secrets.GITLAB_DOCKER_REGISTRY_USER }}

.github/workflows/release.yml

@@ -27,7 +27,7 @@ jobs:
       # the following action is equivalent to
       # echo "$DOCKER_HUB_SECRET" | docker login --username "$DOCKER_HUB_USERNAME" --password-stdin
       - name: Login to Docker Hub
-        uses: docker/login-action@v3
+        uses: docker/login-action@v4
         with:
           username: ${{ secrets.DOCKER_HUB_USERNAME }}
           password: ${{ secrets.DOCKER_HUB_SECRET }}
@@ -37,7 +37,7 @@ jobs:
           make release USER=docker.io/openwisp
 
       - name: Login to GitLab Container Registry
-        uses: docker/login-action@v3
+        uses: docker/login-action@v4
         with:
           registry: registry.gitlab.com
           username: ${{ secrets.GITLAB_DOCKER_REGISTRY_USER }}