Bump numpy from 1.19.1 to 1.22.0 in /doc

Bumps [numpy](https://github.com/numpy/numpy) from 1.19.1 to 1.22.0.
- [Release notes](https://github.com/numpy/numpy/releases)
- [Changelog](https://github.com/numpy/numpy/blob/main/doc/RELEASE_WALKTHROUGH.rst)
- [Commits](numpy/numpy@v1.19.1...v1.22.0)

---
updated-dependencies:
- dependency-name: numpy
  dependency-type: direct:production
...

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

Author: dependabot[bot]

doc/requirements.txt

@@ -1,4 +1,4 @@
-numpy==1.19.1
+numpy==1.22.0
 PyQt5==5.15.0
 PyQt5-sip==12.8.0
 QtPy==1.9.0