MNT: (deps): Bump matplotlib from 3.9.1 to 3.9.2 in /ci

Bumps [matplotlib](https://github.com/matplotlib/matplotlib) from 3.9.1 to 3.9.2.
- [Release notes](https://github.com/matplotlib/matplotlib/releases)
- [Commits](matplotlib/matplotlib@v3.9.1...v3.9.2)

---
updated-dependencies:
- dependency-name: matplotlib
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

ci/requirements.txt

@@ -1,5 +1,5 @@
 python>=3.7
-matplotlib==3.9.1
+matplotlib==3.9.2
 numpy==2.1.0
 pandas==2.2.2
 netcdf4==1.7.1.post1