actions: allow creation of the arm64 container

Author: grampelberg

.github/workflows/build.yml

@@ -79,7 +79,7 @@ jobs:
         arch:
           - amd64
           # The emulated arm64 builds are painfully slow (90m last time). Skip them until we have dedicated linux-arm64 hardware.
-          # - arm64
+          - arm64
 
         include:
           - arch: amd64

.github/workflows/release.yml

@@ -45,6 +45,9 @@ jobs:
           path: /tmp/digests
           pattern: digests-*
 
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+
       - name: buildx
         uses: docker/setup-buildx-action@v3