chore(deps): bump docker/build-push-action from 6.19.2 to 7.3.0 (#12)

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 6.19.2 to 7.3.0.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](docker/build-push-action@10e90e3...53b7df9)

---
updated-dependencies:
- dependency-name: docker/build-push-action
  dependency-version: 7.3.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/build.yml

@@ -49,7 +49,7 @@ jobs:
         uses: docker/setup-buildx-action@bb05f3f5519dd87d3ba754cc423b652a5edd6d2c # v4.2.0
 
       - name: Build proxy image (multi-platform, no push)
-        uses: docker/build-push-action@10e90e3645eae34f1e60eeb005ba3a3d33f178e8 # v6
+        uses: docker/build-push-action@53b7df96c91f9c12dcc8a07bcb9ccacbed38856a # v7.3.0
         with:
           context: .
           file: docker/proxy.Dockerfile

.github/workflows/deploy.yml

@@ -55,7 +55,7 @@ jobs:
           echo "SHORT_SHA=${SHORT_SHA}" >> "$GITHUB_ENV"
 
       - name: Build and push proxy image (multi-platform)
-        uses: docker/build-push-action@10e90e3645eae34f1e60eeb005ba3a3d33f178e8 # v6
+        uses: docker/build-push-action@53b7df96c91f9c12dcc8a07bcb9ccacbed38856a # v7.3.0
         with:
           context: .
           file: docker/proxy.Dockerfile