GH-109653: Defer import of `importlib.metadata._adapters` #106829

Job	Run time
Check for source changes	9s
Check if generated files are up to date	4m 44s
Address sanitizer	7m 42s
Ubuntu SSL tests with OpenSSL (1.1.1w)	1m 59s
Ubuntu SSL tests with OpenSSL (3.0.13)	2m 9s
CIFuzz	0s
Hypothesis tests on Ubuntu	6m 12s
Ubuntu SSL tests with OpenSSL (3.1.5)	2m 6s
Ubuntu SSL tests with OpenSSL (3.2.1)	2m 12s
Windows (free-threading) / build and test (x64)	27m 12s
Windows (free-threading) / build (arm64)	2m 45s
Windows (free-threading) / build and test (x86)	24m 44s
macOS / build and test (macos-14)	8m 10s
macOS / build and test (macos-13)	10m 25s
macOS (free-threading) / build and test (macos-14)	9m 10s
Ubuntu / build and test	7m 58s
Ubuntu (free-threading) / build and test	9m 5s
Windows / build and test (x64)	15m 6s
Windows / build and test (x86)	15m 27s
Thread sanitizer / Thread sanitizer	5m 26s
Thread sanitizer (free-threading) / Thread sanitizer	7m 29s
WASI / build and test	9m 56s
Windows / build (arm64)	3m 1s
Docs / Docs	2m 2s
Docs / Docs (Oldest Sphinx)	1m 33s
Docs / Doctest	39m 54s
All required checks pass	3s
	3h 46m 39s

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