update Pants' own Python to 3.11 #24611

Job	Run time
Classify changes	4s
Bootstrap Pants, test and lint Rust (Linux-x86_64)	2m 4s
Bootstrap Pants, test Rust (macOS12-x86_64)	3m 28s
Build wheels (Linux-ARM64)	22m 29s
Bootstrap Pants, test Rust (Linux-ARM64)	2m 16s
Build wheels (Linux-x86_64)	13m 59s
Build wheels (macOS10-15-x86_64)	11m 59s
Build wheels (macOS11-ARM64)	7m 8s
Ensure PR has release notes	4s
Lint Python and Shell	4m 51s
Test Python (Linux-x86_64) Shard 0/10	17m 26s
Test Python (Linux-x86_64) Shard 2/10	16m 47s
Test Python (Linux-x86_64) Shard 1/10	16m 35s
Test Python (Linux-x86_64) Shard 3/10	15m 37s
Test Python (Linux-x86_64) Shard 4/10	27m 42s
Test Python (Linux-x86_64) Shard 5/10	13m 10s
Test Python (Linux-x86_64) Shard 6/10	10m 8s
Test Python (Linux-x86_64) Shard 7/10	14m 34s
Test Python (Linux-x86_64) Shard 8/10	14m 34s
Test Python (Linux-x86_64) Shard 9/10	11m 10s
Test Python (Linux-ARM64)	11m 10s
Test Python (macOS12-x86_64)	13m 34s
Set Merge OK	1s
Merge OK	1s
	4h 10m 51s

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