Bump mistune from 3.1.3 to 3.2.1 in /ci

Bumps [mistune](https://github.com/lepture/mistune) from 3.1.3 to 3.2.1.
- [Release notes](https://github.com/lepture/mistune/releases)
- [Changelog](https://github.com/lepture/mistune/blob/main/docs/changes.rst)
- [Commits](lepture/mistune@v3.1.3...v3.2.1)

---
updated-dependencies:
- dependency-name: mistune
  dependency-version: 3.2.1
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

ci/requirements.txt

@@ -1419,9 +1419,9 @@ mdurl==0.1.2 \
     --hash=sha256:84008a41e51615a49fc9966191ff91509e3c40b939176e643fd50a5c2196b8f8 \
     --hash=sha256:bb413d29f5eea38f31dd4754dd7377d4465116fb207585f97bf925588687c1ba
     # via markdown-it-py
-mistune==3.1.3 \
-    --hash=sha256:1a32314113cff28aa6432e99e522677c8587fd83e3d51c29b82a52409c842bd9 \
-    --hash=sha256:a7035c21782b2becb6be62f8f25d3df81ccb4d6fa477a6525b15af06539f02a0
+mistune==3.2.1 \
+    --hash=sha256:78cdb0ba5e938053ccf63651b352508d2efa9411dc8810bfb05f2dc5140c0048 \
+    --hash=sha256:7c8e5501d38bac1582e067e46c8343f17d57ea1aaa735823f3aba1fd59c88a28
     # via
     #   -r nmodl_requirements.txt
     #   nbconvert