feat: add ubuntu build ci

Author: ensan-hcl

.github/workflows/swift.yml

@@ -22,6 +22,22 @@ jobs:
       - name: Test
         run: swift test --package-path Core
 
+  ubuntu-build:
+    name: Build and Test on Ubuntu
+    runs-on: ubuntu-22.04
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          submodules: true
+      - name: Setup Swift 6.1
+        uses: swift-actions/setup-swift@v1
+        with:
+          swift-version: "6.1"
+      - name: Build
+        run: swift build --package-path Core
+      - name: Test
+        run: swift test --package-path Core
+
   xcodebuild-test:
     name: Xcodebuild test on macOS
     runs-on: macos-15