Implement PEP 688: Making the buffer protocol accessible in Python

[JelleZijlstra]

PEP-688 has just been accepted. I will use this issue to track its implementation in CPython.

Linked PRs

• gh-102500: Implement PEP 688 #102521
• gh-102500: Document PEP 688 #102571
• gh-102500: Add PEP 688 and 698 to the 3.12 release highlights #104174
• gh-102500: Remove mention of bytes shorthand #104281
• [3.11] gh-102500: Remove mention of bytes shorthand (#104281) #104288
• [3.11] gh-102500: collections.abc.Buffer doesn't exist in 3.11 #104317

[JelleZijlstra]

All done!