Backport of 8d4ec99 from main.

Backport of d0d5960 from main.

…vior change for incomplete entities.

Backport of 7b80b21 from main.

…r forkserver mode.

This variable should only be set once. Under forkserver, this module
was getting executed multiple times, causing nested temporary dirs
that didn't clean up properly, raising FileNotFoundError.

This similar to #27890 although a slightly different cause.

Backport of cd6278c from main.

….14+.

python/cpython#136809 made `color` default to
True in ArgumentParser.

Backport of d0d85cd from main.

… Postgres.

Regression in a16eedc.

The UNNEST strategy is affected by the same problem bulk_update has wrt/
to silent data truncation due to its usage of db_type which always returns
a parametrized subtype.

Backport of d6ae2ed from main.

Backport of f6fd35f from main.