add aarch64 build

Signed-off-by: Bartosz Bezak <bartosz@stackhpc.com>

Author: bbezak

.github/workflows/docker.yaml

@@ -38,7 +38,7 @@ jobs:
         with:
           cache-key: os-capacity
           context: .
-          platforms: linux/amd64
+          platforms: linux/amd64,linux/arm64
           push: true
           tags: ${{ steps.image-meta.outputs.tags }}
           labels: ${{ steps.image-meta.outputs.labels }}