PYTHON-5539 Fix installation of pymongocrypt from source #8193

Job	Run time
CPython pypy-3.10-ubuntu-latest	12m 40s
CPython 3.13t-ubuntu-latest	11m 38s
static	1m 32s
CPython 3.9-ubuntu-latest	12m 30s
Link Check	2m 42s
Typing Tests (3.9)	53s
DocTest	1m 4s
Docs Checks	39s
Typing Tests (3.11)	51s
Test using minimum dependencies and supported Python	34s
Make an sdist	20s
Test async's minimum dependencies and Python	45s
Install from SDist and Test	55s
	47m 3s

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