Bump the Swift image for the integration tests too

Author: gwynne

.github/workflows/test.yml

@@ -63,7 +63,7 @@ jobs:
           - postgres-image: postgres:13
             postgres-auth: trust
     container:
-      image: swift:6.1-noble
+      image: swift:6.2-noble
       volumes: [ 'pgrunshare:/var/run/postgresql' ]
     runs-on: ubuntu-latest
     env: