Fix Gitea build: use ./hs wrapper, cache .stack-root, run upx on host

.gitea/workflows/build.yml

@@ -9,8 +9,7 @@ jobs:
   build:
     runs-on: ubuntu-latest
     env:
-      IMAGE: ghcr.io/flipstone/haskell-tools:debian-ghc-9.10.3-5d6640d
-      STACK_ROOT: /tmp/.stack-root
+      CONVERGE_HASKELL_TOOLS_IMAGE: ghcr.io/flipstone/haskell-tools:debian-ghc-9.10.3-5d6640d
     steps:
       - name: Checkout
         uses: actions/checkout@v4
@@ -18,35 +17,25 @@ jobs:
       - name: Cache Stack
         uses: actions/cache@v4
         with:
-          path: /tmp/.stack-root
+          path: .stack-root
           key: stack-${{ runner.os }}-${{ hashFiles('stack.yaml', 'package.yaml', 'converge.cabal') }}
           restore-keys: stack-${{ runner.os }}-
 
       - name: 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
+          mkdir -p .stack-root build
+          ./hs stack build --copy-bins --local-bin-path /work/build
 
       - name: Compress with UPX
         run: |
-          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_ARCHIVE="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
+            curl -fsSL "https://github.com/upx/upx/releases/download/v${UPX_VERSION}/${UPX_ARCHIVE}" \
+              | tar -xJ -C /tmp
           fi
-              "${UPX_DIR}/upx" /work/build/converge
-            '
+          ${UPX_DIR}/upx build/converge
 
       - name: Upload artifact
         uses: actions/upload-artifact@v4