Add -failfast to CI test command

Stops on the first test failure instead of running the full suite,
making it faster to identify issues.

https://claude.ai/code/session_01CsyRwSkRxBcQoaQFVkMQsJ

Author: claude

.github/workflows/ci.yml

@@ -57,7 +57,7 @@ jobs:
       run: go run ./cmd/sqlc-test-setup start
 
     - name: test ./...
-      run: gotestsum --junitfile junit.xml -- --tags=examples -timeout 20m ./...
+      run: gotestsum --junitfile junit.xml -- --tags=examples -timeout 20m -failfast ./...
       env:
         CI_SQLC_PROJECT_ID: ${{ secrets.CI_SQLC_PROJECT_ID }}
         CI_SQLC_AUTH_TOKEN: ${{ secrets.CI_SQLC_AUTH_TOKEN }}