fix(ci): build static natively with musl on the build host (drop container-build)

container-build=true runs the native-image inside a Mandrel container,
but in the act runner the workspace mount doesn't resolve
(/workspace/... is a container path, not a host path), so the Mandrel
container can't see shot-crafter-calculator-1.0.0-runner.jar.

Fix: install musl + musl-tools in the CI container, build locally.
Quarkus 3.x's binary-type=STATIC will then produce a genuinely static
binary linked against musl, which has no dependency on the host's
glibc and runs cleanly on quarkus-micro-image:2.0 (UBI 9, glibc 2.34).

.gitea/workflows/ci.yml

@@ -21,10 +21,10 @@ jobs:
       image: maven:3.9.6-eclipse-temurin-21
       options: --memory=8g
     steps:
-      - name: Install git, node, gcc, docker, buildx, and basic tools
+      - name: Install git, node, gcc, musl, docker, buildx, and basic tools
         run: |
           apt-get update
-          apt-get install -y git curl ca-certificates build-essential zlib1g-dev docker.io docker-buildx
+          apt-get install -y git curl ca-certificates build-essential zlib1g-dev musl musl-tools docker.io docker-buildx
           curl -fsSL https://deb.nodesource.com/setup_22.x | bash -
           apt-get install -y nodejs
           rm -rf /var/lib/apt/lists/*
@@ -33,6 +33,7 @@ jobs:
           gcc --version
           docker --version
           docker buildx version
+          musl-gcc --version 2>/dev/null || echo "musl-gcc not present (binary-type=STATIC won't produce static binaries)"
 
       - name: Checkout
         uses: actions/checkout@v4
@@ -61,7 +62,7 @@ jobs:
           restore-keys: ${{ runner.os }}-node-
 
       - name: Build (Native)
-        run: mvn package -Pnative -B -DskipTests -Dquarkus.native.native-image-xmx=4g -Dquarkus.native.binary-type=STATIC -Dquarkus.native.container-build=true
+        run: mvn package -Pnative -B -DskipTests -Dquarkus.native.native-image-xmx=4g -Dquarkus.native.binary-type=STATIC
 
       - name: Verify native binary
         run: |