Add Swift Source Compatibility CI workflow (#191)

Author: leogdion

.github/workflows/swift-source-compat.yml

@@ -0,0 +1,31 @@
+name: Swift Source Compatibility
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+  workflow_dispatch:
+
+jobs:
+  swift-source-compat-suite:
+    name: Test Swift ${{ matrix.container }} For Source Compatibility Suite
+    runs-on: ubuntu-latest
+    if: ${{ !contains(github.event.head_commit.message, 'ci skip') }}
+    continue-on-error: ${{ contains(matrix.container, 'nightly') }}
+
+    strategy:
+      fail-fast: false
+      matrix:
+        container:
+          - swift:6.1
+          - swift:6.2
+          - swiftlang/swift:nightly-6.3-noble
+
+    container: ${{ matrix.container }}
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Test Swift 6.x For Source Compatibility
+        run: swift build --disable-sandbox --verbose --configuration release

Package.swift

@@ -62,14 +62,6 @@ let swiftSettings: [SwiftSetting] = [
 
   // Enhanced compiler checking
   .unsafeFlags([
-    // Enable concurrency warnings
-    "-warn-concurrency",
-    // Enable actor data race checks
-    "-enable-actor-data-race-checks",
-    // Complete strict concurrency checking
-    "-strict-concurrency=complete",
-    // Enable testing support
-    "-enable-testing",
     // Warn about functions with >100 lines
     "-Xfrontend", "-warn-long-function-bodies=100",
     // Warn about slow type checking expressions