[ci] remove matrix

.github/workflows/docker.yaml

@@ -12,13 +12,6 @@ jobs:
     permissions:
       contents: read
       packages: write
-    strategy:
-      fail-fast: false
-      matrix:
-        platform:
-          - linux/amd64
-          - linux/arm64
-          - linux/riscv64
     runs-on: ubuntu-latest
     steps:
       - name: Set up Docker Buildx
@@ -56,7 +49,7 @@ jobs:
           context: .
           push: true
           pull: true
-          platforms: ${{ matrix.platform }}
+          platforms: linux/amd64, linux/arm64, linux/riscv64
           labels: ${{ steps.meta.outputs.labels }}
           sbom: true
           provenance: true