Fix Gitea Actions workflow: use docker run instead of container to avoid missing node

.gitea/workflows/build.yml

@@ -8,9 +8,8 @@ on:
 jobs:
   build:
     runs-on: ubuntu-latest
-    container:
-      image: ghcr.io/flipstone/haskell-tools:debian-ghc-9.10.3-5d6640d
     env:
+      IMAGE: ghcr.io/flipstone/haskell-tools:debian-ghc-9.10.3-5d6640d
       STACK_ROOT: /tmp/.stack-root
     steps:
       - name: Checkout
@@ -24,18 +23,34 @@ jobs:
           restore-keys: stack-${{ runner.os }}-
 
       - name: Build
-        run: stack build --copy-bins --local-bin-path /tmp/build
+        run: |
+          docker run --rm \
+            -v "$(pwd):/work" \
+            -v "/tmp/.stack-root:/stack-root" \
+            -e STACK_ROOT=/stack-root \
+            -w /work \
+            "$IMAGE" \
+            stack build --copy-bins --local-bin-path /work/build
 
       - name: Compress with UPX
         run: |
-          UPX_VERSION="5.1.1"
-          curl -fsSL "https://github.com/upx/upx/releases/download/v${UPX_VERSION}/upx-${UPX_VERSION}-amd64_linux.tar.xz" \
-            | tar -xJ -C /tmp
-          /tmp/upx-${UPX_VERSION}-amd64_linux/upx /tmp/build/converge
+          docker run --rm \
+            -v "$(pwd):/work" \
+            -w /work \
+            "$IMAGE" \
+            bash -c '
+              UPX_VERSION="5.1.1"
+              UPX_URL="https://github.com/upx/upx/releases/download/v${UPX_VERSION}/upx-${UPX_VERSION}-amd64_linux.tar.xz"
+              UPX_DIR="/tmp/upx-${UPX_VERSION}-amd64_linux"
+              if [ ! -x "${UPX_DIR}/upx" ]; then
+                curl -fsSL "${UPX_URL}" | tar -xJ -C /tmp
+              fi
+              "${UPX_DIR}/upx" /work/build/converge
+            '
 
       - name: Upload artifact
         uses: actions/upload-artifact@v4
         with:
           name: converge
-          path: /tmp/build/converge
+          path: build/converge
           compression-level: 0