Bump numpy from 1.21.3 to 1.21.4 in /requirements/CI-tests-pip

Bumps [numpy](https://github.com/numpy/numpy) from 1.21.3 to 1.21.4.
- [Release notes](https://github.com/numpy/numpy/releases)
- [Changelog](https://github.com/numpy/numpy/blob/main/doc/HOWTO_RELEASE.rst.txt)
- [Commits](numpy/numpy@v1.21.3...v1.21.4)

---
updated-dependencies:
- dependency-name: numpy
  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

@@ -3,7 +3,7 @@ colorama==0.4.4
 daiquiri==3.0.1
 humanize==3.12.0
 matplotlib==3.4.3
-numpy==1.21.3
+numpy==1.21.4
 pandas==1.2.5
 pytest==6.2.5
 pytest-xdist==2.4.0