make memoryview thread safe in free-threading

[kumaraditya303]

memoryview is currently not safe against free-threading especially concurrent releasing the memoryviews. This issue track work to make it thread safe.

This is a follow-up to #127412 (review).

[picnixz]

Do you think it should be a feature (main only) or a bug fix (3.13+)?

[kumaraditya303]

For now I'll target main, if it doesn't need too many changes it may be backported.

[picnixz]

Ok. I'll apply the labels after we decided whether we should backport it or not.

[ZeroIntensity]

FWIW, we typically do backport thread safety fixes to 3.13. We should probably merge gh-127412 before putting up anything new to prevent conflicts.