update makedoc using mistune v3

[fmigneault]

Fixes #721
Requires lepture/mistune#375

[mr-c]

@fmigneault I copied in the stubs from the mistune PR for now, so we don't have to wait on the new release.

Can you look into the test failures?

[fmigneault]

@mr-c
One of the failing test is test_multiline_list_entries_without_indention where the expected <li></li> tags are instead represented by <ul></ul>. If this is acceptable, we can simply replace the test string.
Nevermind, it is only a diff about how newlines are applied. I will adjust the test.

The other is the checksum comparison that must be updated if we are satisfied with the new output format.

[mr-c]

Thank you @fmigneault !