Fix image-build: static docker-cli for non-root runner

.forgejo/workflows/image-build.yaml

@@ -19,11 +19,13 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
 
-      - name: Install docker CLI
+      - name: Install docker CLI (static binary)
         run: |
           set -eu
-          apk add --no-cache docker-cli
+          mkdir -p "${HOME}/bin"
-          docker version
+          wget -qO- https://download.docker.com/linux/static/stable/x86_64/docker-27.3.1.tgz             | tar xz --strip-components=1 -C "${HOME}/bin" docker/docker
+          echo "${HOME}/bin" >> "${GITHUB_PATH}"
+          "${HOME}/bin/docker" version
 
       - name: Login to Forgejo registry
         run: |