[Chore] Build and publish Telemetrygen images with multiarch support (open-telemetry#29905)

**Description:** <Describe what has changed.>
This PR updates the Telemetrygen workflow to build and publish multiarch
images.

Resolves
open-telemetry#30072

**Testing:** <Describe what testing was performed and which tests were
added.>

ToDo

**Documentation:** <Describe the documentation added.>

---------

Signed-off-by: Ishwar Kanse <ikanse@redhat.com>

Author: Ishwar Kanse

.github/workflows/telemetrygen.yml

@@ -17,12 +17,17 @@ jobs:
     if: ${{ github.actor != 'dependabot[bot]' && github.actor != 'renovate[bot]' }}
     steps:
       - uses: actions/checkout@v4
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
       - name: Build telemetrygen
         uses: docker/build-push-action@v5
         with:
           context: cmd/telemetrygen
           push: false
           tags: ghcr.io/open-telemetry/opentelemetry-collector-contrib/telemetrygen:dev
+          platforms: linux/amd64,linux/arm64,linux/s390x,linux/ppc64le
 
   publish-latest:
     runs-on: ubuntu-latest
@@ -31,6 +36,10 @@ jobs:
       packages: write
     steps:
       - uses: actions/checkout@v4
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
       - name: Login to GitHub Container Registry
         uses: docker/login-action@v3
         with:
@@ -43,6 +52,7 @@ jobs:
           context: cmd/telemetrygen
           push: true
           tags: ghcr.io/open-telemetry/opentelemetry-collector-contrib/telemetrygen:latest
+          platforms: linux/amd64,linux/arm64,linux/s390x,linux/ppc64le
 
   publish-stable:
     runs-on: ubuntu-latest
@@ -51,6 +61,10 @@ jobs:
       packages: write
     steps:
       - uses: actions/checkout@v4
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
       - name: Set Release Tag
         id: github_tag
         run: ./.github/workflows/scripts/set_release_tag.sh
@@ -61,8 +75,9 @@ jobs:
           username: ${{ github.repository_owner }}
           password: ${{ secrets.GITHUB_TOKEN }}
       - name: Push telemetrygen to Github packages
-        run: |
-          docker build cmd/telemetrygen -t ghcr.io/open-telemetry/opentelemetry-collector-contrib/telemetrygen:$RELEASE_TAG
-          docker push ghcr.io/open-telemetry/opentelemetry-collector-contrib/telemetrygen:$RELEASE_TAG
-        env:
-          RELEASE_TAG: ${{ steps.github_tag.outputs.tag }}
+        uses: docker/build-push-action@v5
+        with:
+          context: cmd/telemetrygen
+          push: true
+          tags: ghcr.io/open-telemetry/opentelemetry-collector-contrib/telemetrygen:${{ steps.github_tag.outputs.tag }}
+          platforms: linux/amd64,linux/arm64,linux/s390x,linux/ppc64le