test: Add e2e tests for cred setup on workflow editor (no-changelog) (#8245)

## Summary

Follow-up to https://github.com/n8n-io/n8n/pull/8240

Adds e2e tests for the template credential setup in workflow editor


## Related tickets and issues

https://linear.app/n8n/issue/ADO-1463/feature-enable-users-to-close-and-re-open-the-setup

cypress/composables/setup-workflow-credentials-button.ts

@@ -0,0 +1,5 @@
+/**
+ * Getters
+ */
+
+export const getSetupWorkflowCredentialsButton = () => cy.get(`button:contains("Set up Template")`);