Tests

Bump version to 1.16.0+dev (#18509) #14583

Job	Run time
Test mypyc suite with 32-bit Python	9m 19s
Test suite with py39-ubuntu, mypyc-compiled	19m 22s
Test suite with py39-windows-64	21m 2s
Test suite with py310-ubuntu	17m 33s
Test suite with py311-ubuntu, mypyc-compiled	16m 35s
Test suite with py312-ubuntu, mypyc-compiled	18m 6s
Test suite with py313-ubuntu, mypyc-compiled	18m 6s
mypyc runtime tests with py39-macos	6m 2s
Type check our own code (py39-ubuntu)	2m 7s
Type check our own code (py39-windows-64)	2m 43s
Formatting and code style with Black + ruff	1m 42s
	2h 12m 37s

Provide feedback