build(deps): bump actions/upload-artifact from 5 to 6 (#4233)

Author: dependabot[bot]

.github/workflows/gen.yml

@@ -32,7 +32,7 @@ jobs:
         PG_PASSWORD: postgres
         PG_PORT: ${{ job.services.postgres.ports['5432'] }}
     - name: Save results
-      uses: actions/upload-artifact@v5
+      uses: actions/upload-artifact@v6
       with:
         name: sqlc-pg-gen-results
         path: gen