docs/qapidoc: linting fixes

docs/qapidoc: linting fixes

This restores the linting baseline in qapidoc. The order of some imports
change slightly here due to configuring isort a little better:
previously, isort was having difficulty understanding that "compat" and
"qapidoc_legacy" were local modules because docs/sphinx "isn't a python
package". Configuring this manually, isort chooses a different import
ordering, which _is_ intentional here.

Also: extra ignores are added for pylint. The most recent versions of
pylint don't require these ignores, but the oldest versions we support
do, so in the extra ignores go.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-id: 20250604200354.459501-3-jsnow@redhat.com