Update ipython requirement from <7.19,>=7.12 to >=7.12,<7.20

Updates the requirements on [ipython](https://github.com/ipython/ipython) to permit the latest version.
- [Release notes](https://github.com/ipython/ipython/releases)
- [Commits](https://github.com/ipython/ipython/compare/7.12.0...7.19.0)

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

requirements.txt

 # Helpers
 pyprof2calltree==1.4.5
 ipdb==0.13.4
-ipython>=7.12,<7.19
+ipython>=7.12,<7.20
 
 # Country data
 pycountry>=19.8,<20.8