Thanks Tim Graham for the review.

mysqlclient 1.3.7 fixes the test failures caused by 1.3.6.

Thanks Corey Farwell for the report and Tim Graham for the review.
Thanks also to Inada Naoki for creating and maintaining mysqlclient.

Avoided introducing a new regex-based SQL splitter in the migrations
framework, before we're bound by backwards compatibility.

Adapted this change to the legacy "initial SQL data" feature, even
though it's already deprecated, in order to facilitate the transition
to migrations.

sqlparse becomes mandatory for RunSQL on some databases (all but
PostgreSQL). There's no API to provide a single statement and tell
Django not to attempt splitting. Since we have a more robust splitting
implementation, that seems like a good tradeoff. It's easier to add a
new keyword argument later if necessary than to remove one.

Many people contributed to both tickets, thank you all, and especially
Claude for the review.

Refs #22401.

Revert "Fixed #22401 -- Deprecated regular expression parsing of initial SQL in favor of installing sqlparse."

This reverts commit 071c9337.

This introduced a regression on MySQL and custom SQL is deprecated.

Fixed #22401 -- Deprecated regular expression parsing of initial SQL in favor of installing sqlparse.

Thanks Tim Graham for the report