Bump matplotlib from 3.7.1 to 3.9.4

Bumps [matplotlib](https://github.com/matplotlib/matplotlib) from 3.7.1 to 3.9.4.
- [Release notes](https://github.com/matplotlib/matplotlib/releases)
- [Commits](matplotlib/matplotlib@v3.7.1...v3.9.4)

---
updated-dependencies:
- dependency-name: matplotlib
  dependency-version: 3.9.4
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

requirements_test.txt

@@ -4,7 +4,7 @@
 
 numpy>=1.18.5,<1.27
 scipy==1.10.1
-matplotlib==3.7.1
+matplotlib==3.9.4
 scikit-learn==1.6.1
 six==1.17.0
 Pillow==11.1.0