Fix image workflow: use short SHA for Forgejo archive checkout

.forgejo/workflows/image.yaml

@@ -33,9 +33,11 @@ jobs:
         run: |
           set -eu
           REF="${GITHUB_SHA:-main}"
+          SHORT="${REF:0:7}"
           mkdir -p buildctx "${HOME}/bin"
+          # Forgejo archive endpoint accepts short SHA; full SHA can hang.
           wget -qO /tmp/primary.tar.gz \
-            "https://forgejo.coulomb.social/${GITHUB_REPOSITORY}/archive/${REF}.tar.gz"
+            "https://forgejo.coulomb.social/${GITHUB_REPOSITORY}/archive/${SHORT}.tar.gz"
           tar xzf /tmp/primary.tar.gz -C buildctx --strip-components=1
           BUILD_ARGS=()
           for spec in ${EXTRA_REPOS}; do
@@ -53,7 +55,6 @@ jobs:
             | tar xz --strip-components=1 -C "${HOME}/bin" docker/docker
           export PATH="${HOME}/bin:${PATH}"
           echo "${REGISTRY_TOKEN}" | docker login "${REGISTRY}" -u "${REGISTRY_USER}" --password-stdin
-          SHORT="${REF:0:7}"
           IMAGE="${REGISTRY}/${IMAGE_NAME}"
           docker build "${BUILD_ARGS[@]}" \
             -t "${IMAGE}:latest" -t "${IMAGE}:main-${SHORT}" buildctx