Coverage: Implement fail_under #2300

Job	Run time
Run tests (3.10.4)	9s
Run tests (3.10)	5s
Run tests (3.12.0)	7s
Run tests (3.12)	10s
Run tests (3.9)	9s
Run tests (3.11)	12s
Run tests (3.11.0)	9s
Run tests (3.9.12)	9s
Run tests (pypy3.10)	11s
Run tests (3.14)	5s
Run tests (3.13.0)	8s
Run tests (3.13)	7s
Run tests (pypy3.9)	10s
Run tests (pypy3.11)	15s
Create an issue if daily tests failed	1s
Report coverage	1s
	2m 8s

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