build(deps): 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/agent-image.yaml

@@ -51,7 +51,7 @@ jobs:
         uses: docker/setup-buildx-action@v3
 
       - name: Log in to GHCR
-        uses: docker/login-action@v3
+        uses: docker/login-action@v4
         with:
           registry: ghcr.io
           username: ${{ github.actor }}

.github/workflows/build.yaml

@@ -17,7 +17,7 @@ jobs:
       # Multi-arch builds for releases happen in release.yaml via GoReleaser
       # (uses native runners + Go cross-compile, not QEMU). This job is a fast
       # PR smoke test — single-platform, host-arch.
-      - uses: docker/login-action@v3
+      - uses: docker/login-action@v4
         if: github.event_name == 'push'
         with:
           registry: ghcr.io

.github/workflows/release.yaml

@@ -30,7 +30,7 @@ jobs:
         uses: docker/setup-buildx-action@v3
 
       - name: Log in to GitHub Container Registry
-        uses: docker/login-action@v3
+        uses: docker/login-action@v4
         with:
           registry: ghcr.io
           username: ${{ github.actor }}
@@ -108,7 +108,7 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Log in to GitHub Container Registry
-        uses: docker/login-action@v3
+        uses: docker/login-action@v4
         with:
           registry: ghcr.io
           username: ${{ github.actor }}