qapi: Dumb down QAPISchema.lookup_entity()

QAPISchema.lookup_entity() takes an optional type argument, a subtype
of QAPISchemaDefinition, and returns that type or None.  Callers can
use this to save themselves an isinstance() test.

The only remaining user of this convenience feature is .lookup_type().
But we don't actually save anything anymore there: we still need the
isinstance() to help mypy over the hump.

Drop the .lookup_entity() argument, and adjust .lookup_type().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-ID: <20240315152301.3621858-26-armbru@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
[Commit message typo fixed]
1 file changed