Bump docker/setup-buildx-action from 3 to 4

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

---
updated-dependencies:
- dependency-name: docker/setup-buildx-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/nightly_build.yaml

@@ -24,7 +24,7 @@ jobs:
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v4
       - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v3
+        uses: docker/setup-buildx-action@v4
       - name: Install regctl
         uses: regclient/actions/regctl-installer@main
       - name: Build image

.github/workflows/pr_build.yaml

@@ -185,6 +185,6 @@ jobs:
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v4
       - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v3
+        uses: docker/setup-buildx-action@v4
       - name: Build image
         run: make docker-build

.github/workflows/release_build.yaml

@@ -57,7 +57,7 @@ jobs:
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v4
       - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v3
+        uses: docker/setup-buildx-action@v4
       - name: Build artifact (x86_64)
         run: make build
       - name: Compress artifact (x86_64)