Bump matplotlib from 3.4.2 to 3.4.3 in /requirements/CI-tests-pip

Bumps [matplotlib](https://github.com/matplotlib/matplotlib) from 3.4.2 to 3.4.3.
- [Release notes](https://github.com/matplotlib/matplotlib/releases)
- [Commits](matplotlib/matplotlib@v3.4.2...v3.4.3)

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

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

Author: dependabot[bot]

requirements/CI-tests-pip/requirements.txt

@@ -2,7 +2,7 @@ attrs==21.2.0
 colorama==0.4.4
 daiquiri==3.0.0
 humanize==3.11.0
-matplotlib==3.4.2
+matplotlib==3.4.3
 numpy==1.21.2
 pandas==1.2.4
 pytest==6.2.4