test: run four Endform tests concurrently

All 19 tests passed with two concurrent Endform tests.
Raise the limit to four to check parallel execution

Author: augustoccesar

packages/testing/playwright/endform.config.ts

@@ -3,6 +3,6 @@ import { defineEndformConfig } from 'endform';
 
 export default defineEndformConfig({
 	additionalFiles: ['workflows/**/*'],
-	concurrentTestLimits: [{ scope: 'within-suite-run', limit: 2 }],
+	concurrentTestLimits: [{ scope: 'within-suite-run', limit: 4 }],
 	environmentVariables: ['N8N_BASE_URL', 'RESET_E2E_DB', 'E2E_REMOTE_RUNNER'],
 });