PYTHON-5544 Revert changes to base protocol layer #8174

Job	Run time
Make an sdist	16s
Docs Checks	39s
Typing Tests (3.9)	1m 4s
Test async's minimum dependencies and Python	45s
Test using minimum dependencies and supported Python	45s
Typing Tests (3.11)	1m 3s
CPython pypy-3.10-ubuntu-latest	9m 19s
static	3m 6s
CPython 3.13t-ubuntu-latest	9m 19s
CPython 3.9-ubuntu-latest	9m 19s
DocTest	1m 4s
Link Check	3m 46s
Install from SDist and Test	56s
	41m 21s

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