Pin tonistiigi/binfmt image to qemu-v9.2.0.

Something has broken running the latest aarch64 on amd64, so trying to
track down things. The `master` tag pointed to a version that was 2
years old - so we'll bump to something newer. It is also better to have
this pinned anyway.

.github/workflows/docker.yml

@@ -19,6 +19,8 @@ concurrency:
 env:
   # renovate: datasource=docker depName=alpine versioning=docker
   ALPINE_IMAGE: alpine:3.21.2@sha256:56fa17d2a7e7f168a043a2712e63aed1f8543aeafdcee47c58dcffe38ed51099
+  # renovate: datasource=docker depName=tonistiigi/binfmt versioning=docker
+  BINFMT_IMAGE: tonistiigi/binfmt:qemu-v9.2.0@sha256:2ebbaaeb812b8f9d1cd725d2640a25989b2c25506f3665411a92554746f68562
   ARMEDSLACK_VERSIONS: '["12.2","13.1","13.37"]'
   SLACKWAREARM_VERSIONS: '["14.0","14.1","14.2","15.0"]'
   SLACKWAREAARCH64_VERSIONS: '["current"]'
@@ -78,6 +80,8 @@ jobs:
 
       - name: Set up QEMU
         uses: docker/setup-qemu-action@53851d14592bedcffcf25ea515637cff71ef929a # v3.3.0
+        with:
+          image: ${{ env.BINFMT_IMAGE }}
 
       - name: Set up Docker Buildx
         id: buildx