ci: changed the trigger from pull_request_target to pull_request for better security

[nandan-bhat]

Changes

ci: changed the trigger from pull_request_target to pull_request for better security

Checklist

• [x] I have read the Auth0 general contribution guidelines
• [x] I have read the Auth0 Code of Conduct
• [x] All code quality tools/guidelines have been run/followed
• [ ] All relevant assets have been compiled