Bump prompt-toolkit from 3.0.7 to 3.0.8

Bumps [prompt-toolkit](https://github.com/prompt-toolkit/python-prompt-toolkit) from 3.0.7 to 3.0.8.
- [Release notes](https://github.com/prompt-toolkit/python-prompt-toolkit/releases)
- [Changelog](https://github.com/prompt-toolkit/python-prompt-toolkit/blob/master/CHANGELOG)
- [Commits](https://github.com/prompt-toolkit/python-prompt-toolkit/commits)

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

Author: dependabot-preview[bot]

test-requirements.txt

@@ -35,7 +35,7 @@ pathspec==0.8.0           # via black
 pexpect==4.8.0            # via ipython
 pickleshare==0.7.5        # via ipython
 pluggy==0.13.1            # via pytest
-prompt-toolkit==3.0.7     # via ipython
+prompt-toolkit==3.0.8     # via ipython
 ptyprocess==0.6.0         # via pexpect
 py==1.9.0                 # via pytest
 pycodestyle==2.6.0        # via flake8