Replace misaka with mistletoe

[gersona]

fixes #9786

• Replace misaka with mistletoe #9786

Proposed changes

Re-implement the markdown rendering module with the mistletoe library since mikasa is no longer maintained

Checklist

• Lint and unit tests pass locally with my changes.
• I have added tests that prove my fix is effective or that my feature works.
• I have added documentation to describe my feature.
• I have squashed my commits into logic units.
• I have described the changes in the commit messages.

Other information

I need help figuring out how to properly remove the dependency references to mikasa in the pyproject.toml and requirements.py files

[nijel]

Please remove misaka from the requirements in pyproject.toml it should not be needed anymore.

[codecov]

Codecov Report

Attention: Patch coverage is 96.42857% with 2 lines in your changes missing coverage. Please review.

Project coverage is 90.61%. Comparing base (6aee586) to head (765afda).
Report is 2307 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #11905      +/-   ##
==========================================
- Coverage   90.82%   90.61%   -0.21%     
==========================================
  Files         554      581      +27     
  Lines       57306    58966    +1660     
  Branches     9122     9408     +286     
==========================================
+ Hits        52046    53434    +1388     
- Misses       3640     3836     +196     
- Partials     1620     1696      +76     

Files	Coverage Δ
weblate/utils/tests/test_markdown.py	100.00% <100.00%> (ø)
weblate/utils/markdown.py	96.49% <94.44%> (-3.51%)	⬇️

... and 340 files with indirect coverage changes

[accesslint]

There are accessibility issues in these changes.

[nijel]

Scheduled for merge, thanks for your contribution!