Bump numpy from 1.21.0 to 1.22.0 in /docs (#150)

Bumps [numpy](https://github.com/numpy/numpy) from 1.21.0 to 1.22.0.
- [Release notes](https://github.com/numpy/numpy/releases)
- [Changelog](https://github.com/numpy/numpy/blob/main/doc/HOWTO_RELEASE.rst)
- [Commits](numpy/numpy@v1.21.0...v1.22.0)

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

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

docs/requirements.rtd.txt

@@ -12,7 +12,7 @@ pytest-runner==5.1
 click==7.1.1
 geopandas==0.7.0
 matplotlib==3.2.1
-numpy==1.21.0
+numpy==1.22.0
 pandas==1.0.3
 rasterio==1.1.3
 rioxarray==0.0.26