Improve transformer performance

[mikepenz]

• build regexp per transformer only once

[github-actions[bot]]

	Tests	Passed ✅	Skipped ⏭️	Failed ❌
Example Pytest Report	4 ran	2 passed	0 skipped	2 failed

	Test	Result
Example Pytest Report	test_sample.test_which_succeeds	✅ pass
Example Pytest Report	test_sample.test_which_fails	❌ failure
Example Pytest Report	test_sample.test_with_error	❌ failure
Example Pytest Report	test_sample.test_with_flaky_success	✅ pass