PYTHON-5325 - Decrease TestAsyncConcurrency.test_concurrency threshold #2148

Job	Run time
Make SDist	32s
Build wheels for manylinux_x86_64	2m 19s
Build wheels for manylinux_aarch64	11m 42s
Build wheels for manylinux_ppc64le	11m 9s
Build wheels for manylinux_s390x	11m 23s
Build wheels for manylinux_i686	2m 26s
Build wheels for win_amd6	4m 21s
Build wheels for win32	4m 19s
Build wheels for macos	3m 35s
Download Wheels	7s
	51m 53s

Provide feedback