deps(python): bump matplotlib from 3.9.2 to 3.10.8 in /backend

Bumps [matplotlib](https://github.com/matplotlib/matplotlib) from 3.9.2 to 3.10.8.
- [Release notes](https://github.com/matplotlib/matplotlib/releases)
- [Commits](matplotlib/matplotlib@v3.9.2...v3.10.8)

---
updated-dependencies:
- dependency-name: matplotlib
  dependency-version: 3.10.8
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

backend/pyproject.toml

@@ -137,7 +137,7 @@ dev = [
     "coverage==7.13.0",
     "hypothesis==6.103.4",
     "iniconfig==2.0.0",
-    "matplotlib==3.9.2",
+    "matplotlib==3.10.8",
     "mypy==1.17.1",
     "mypy_extensions==1.1.0",
     "pipdeptree==2.23.4",