None of the core backends currently support can_introspect_autofield.
Fixed #21097 - Added DatabaseFeature.can_introspect_autofield
The patch looks good to me, although I can't test this currently.
My only question is whether or not any of our existing backends could/should be able to inspect AutoField?
Many of them certainly could, but whether they will is an exercise for someone who uses and is willing to submit a patch for a given backend. If anyone feels inclined to add this new functionality to a core backend, that can always happen as a separate commit.
The scope of this ticket/pull request is small and intended to only make it possible for a backend to inspect AutoField.
Merged manually. If somebody wants to add AutoField inspection support for other databases then open another ticket for that.