ci(*): update actions to use docker native action (#393)

This pull request updates the workflow configuration files to improve
how QEMU is set up for cross-platform Docker builds. The changes replace
the manual QEMU setup command with the `docker/setup-qemu-action@v3`
GitHub Action, making the setup more streamlined and consistent.

Workflow updates:

*
[`.github/workflows/llvm-build-bump-pr.yml`](diffhunk://#diff-d608eb75b383338d789a8908995e47499214a7cc55a847771ad73800464b18b0L190-R192):
Replaced the manual QEMU setup (`docker run --rm --privileged
multiarch/qemu-user-static --reset -p yes`) with the
`docker/setup-qemu-action@v3` GitHub Action, specifying the platform
using the `matrix.docker.platform` variable.
*
[`.github/workflows/test-cross-platform.yml`](diffhunk://#diff-290907d9a4bcf13181105b134bd1645da5a3ef27c54f148ad5823e6b77e88426L154-R156):
Similarly replaced the manual QEMU setup with the
`docker/setup-qemu-action@v3` GitHub Action, ensuring platform
compatibility for Docker builds.

Author: lumirlumir

.github/workflows/llvm-build-bump-pr.yml

@@ -187,7 +187,9 @@ jobs:
         run: echo ${{ matrix.docker.platform }} ${{ matrix.docker.ubuntu-image }} ${{ matrix.docker.node-name }}
 
       - name: Set up QEMU
-        run: docker run --rm --privileged multiarch/qemu-user-static --reset -p yes
+        uses: docker/setup-qemu-action@v3
+        with:
+          platforms: linux/${{ matrix.docker.platform }}
 
       # Use the oldest ubuntu image version possible for backward compatibility.
       - name: Docker run

.github/workflows/test-cross-platform.yml

@@ -151,7 +151,9 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Set up QEMU
-        run: docker run --rm --privileged multiarch/qemu-user-static --reset -p yes
+        uses: docker/setup-qemu-action@v3
+        with:
+          platforms: linux/${{ matrix.docker.platform }}
 
       - name: Docker run background
         run: docker run -d --name ${{ matrix.docker.node-name }} --platform linux/${{ matrix.docker.platform }} ${{ matrix.docker.ubuntu-image }}/ubuntu:22.04 tail -f /dev/null