ci: Use host runner to avoid Docker-in-Docker issues

- Change runs-on from ubuntu-latest to linux (maps to linux:host)
- Remove container: directive that caused SIGKILL on sibling containers
- Run directly on LXC host which is already Ubuntu
- Add sudo for apt-get commands on host
- Check for existing cargo before installing Rust

.gitea/workflows/build.yml

@@ -12,14 +12,12 @@ env:
 
 jobs:
   build-and-package:
-    runs-on: ubuntu-latest
-    container:
-      image: ubuntu:24.04
+    runs-on: linux
     steps:
       - name: Install system dependencies
         run: |
-          apt-get update -qq
-          apt-get install -y --no-install-recommends \
+          sudo apt-get update -qq
+          sudo apt-get install -y --no-install-recommends \
             curl pkg-config libssl-dev ca-certificates \
             git nodejs npm dpkg-dev python3
 
@@ -30,19 +28,20 @@ jobs:
 
       - name: Install Rust toolchain
         run: |
-          curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y
-          . "$HOME/.cargo/env"
-          rustup default stable
-          echo "$HOME/.cargo/bin" >> "$GITHUB_PATH"
+          if ! command -v cargo &>/dev/null; then
+            curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y
+            . "$HOME/.cargo/env"
+            echo "$HOME/.cargo/bin" >> "$GITHUB_PATH"
+          fi
 
       - name: Build Rust backend (release)
         run: |
-          . "$HOME/.cargo/env"
+          . "$HOME/.cargo/env" 2>/dev/null || true
           cargo build --release
 
       - name: Run Rust tests
         run: |
-          . "$HOME/.cargo/env"
+          . "$HOME/.cargo/env" 2>/dev/null || true
           cargo test --release
 
       - name: Strip binaries