Bump mistune from 3.2.1 to 3.3.0 in /backend

[dependabot]

Bumps mistune from 3.2.1 to 3.3.0.

Release notes

Sourced from mistune's releases.

v3.3.0

   🐞 Bug Fixes

• Resolve O(n^2) DoS in parse_link_text (CWE-400)  -  by bhanugoudm041 (b6b49)
• Resolve O(n^2) DoS in parse_link_text (CWE-400)-Type handling/testing done  -  by bhanugoudm041 (b3af8)
• block: Avoid quadratic ref link scans  -  by @​lepture (2b04d)
• cli: Add entrypoint and utf-8 output  -  by @​lepture (2f244)
• directives: Constrain include targets  -  by @​lepture (1bef3)
• formatting: Avoid quadratic marker scans  -  by @​lepture (96d0f)
• image: Validate figure width option  -  by @​lepture (e3e51)
• inline: Avoid bracket parsing DoS  -  by @​lepture (25f25)
• math: Reject currency patterns and cross-line matches in inline math  -  by @​geopanther (566e1)
• math: Support display and backtick math  -  by @​lepture (1141e)
• renderer: Render plugin list and table nodes  -  by @​lepture (614b0)
• renderer: Block encoded unsafe URL schemes  -  by @​lepture (c7101)
• toc: Avoid generated id collisions  -  by @​lepture (c4093)

   🏎 Performance

• Improve performance  -  by @​lepture (bf95c)

    View changes on GitHub

Changelog

Sourced from mistune's changelog.

Version 3.3.0

Released on Jun 21, 2026

• Improve CommonMark compatibility and parser performance.
• Add command line entrypoint with UTF-8 output.
• Support display and backtick math.
• Render plugin list and table nodes in Markdown renderer.
• Escape leading block markers in Markdown renderer.
• Fix RST renderer for block quotes nested in lists.
• Avoid generated heading ID collisions in TOC.
• Harden URL, image, figure, and include directive handling.
• Fix quadratic scans in inline links, reference links, and formatting markers.
• Fix math escaping, currency pattern matching, and cross-line matching.

Commits

• 15c3b79 chore: release 3.3.0
• bdc01ad tests: increase run time on pypy
• 7cf1814 tests: increase run time for pypy
• 6dfdc3d tests: add more tests
• 17c50f6 chore: fix mypy issues
• 63abe4b chore: use ruff check and format
• e6c1b18 chore: resolve mypy issues
• dcf8902 test(math): cover escaped math output
• c4093c4 fix(toc): avoid generated id collisions
• e3e51de fix(image): validate figure width option
• Additional commits viewable in compare view

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[ems-pr-review]

It looks like you are reviewing a Dependabot upgrade PR! 🛠️
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We aim to merge Dependabot PRs within the below timeframes. The objectives are based on the severity of the security vulnerability we are mitigating with the upgrade:

Severity	Target Merge (days)
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HIGH	14 days
MEDIUM	30 days
LOW	90 days

🎯 Target merge date for this PR: 25/07/2026 🎯

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