Update build-ubuntu.yml

Author: makoni

.github/workflows/build-ubuntu.yml

@@ -11,7 +11,7 @@ jobs:
     name: Build on Ubuntu with Swift ${{matrix.swift}}
     strategy:
       matrix:
-        swift: ["5.10", "5.9", "5.8"]
+        swift: ["6.0", "5.10", "5.9", "5.8"]
     runs-on: ubuntu-latest
     container: 
       image: swift:${{matrix.swift}}