Bump ipython from 7.20.0 to 7.21.0

Bumps [ipython](https://github.com/ipython/ipython) from 7.20.0 to 7.21.0.
- [Release notes](https://github.com/ipython/ipython/releases)
- [Commits](ipython/ipython@7.20.0...7.21.0)

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

Author: dependabot-preview[bot]

test-requirements.txt

@@ -45,7 +45,7 @@ iniconfig==1.1.1
     # via pytest
 ipython-genutils==0.2.0
     # via traitlets
-ipython==7.20.0
+ipython==7.21.0
     # via -r test-requirements.in
 isort==5.7.0
     # via pylint