Tests

Improve error messages when positional argument is missing #21343

Job	Run time
Test mypyc suite with 32-bit Python	9m 47s
Test suite with py314-ubuntu, mypyc-compiled	14m 46s
Test suite with py312-ubuntu	9m 2s
Test suite with py313-ubuntu, mypyc-compiled	14m 27s
Test suite with py314-windows-64	26m 45s
mypyc runtime tests with py313-macos	5m 36s
mypyc runtime tests with py310-ubuntu	6m 32s
Test suite with py314t-ubuntu, mypyc-compiled	16m 20s
Test suite with py311-ubuntu	8m 50s
Parallel tests with py314-ubuntu, interpreted	23m 39s
Test suite with py310-ubuntu, mypyc-compiled	15m 21s
Parallel tests with py314-ubuntu, mypyc-compiled	28m 22s
Type check our own code (py310-windows-64)	2m 34s
Parallel tests with py314-windows-64, interpreted	12m 46s
Formatting and code style with Black + ruff	2m 5s
Type check our own code (py310-ubuntu)	1m 46s
	3h 18m 38s

Provide feedback