Chore: bump watchgod Python package

[tynandebold]

Description

I was noticing some errors on CircleCI and, with thanks to help from @AntonyMilneQB, we deduced the watchgod package needed an update.

Checklist

• Read the contributing guidelines
• Opened this PR as a 'Draft Pull Request' if it is work-in-progress
• Updated the documentation to reflect the code changes
• Added new entries to the RELEASE.md file
• Added tests to cover my changes

[antonymilne]

Looks good!

Worth noting:

• watchgod 0.8 added support for Python 3.10. At some point we should make kedro-viz support Python 3.9+ (currently it's just up to 3.8, not sure whether there's a reason for that or we just haven't tried out higher version yet).
• watchgod is changing name to watchfiles: The plan for watchfiles, née watchgod samuelcolvin/watchfiles#102. Since it's a dependency of uvicorn, probably best to see how they handle this in future (and maybe even remove our explicit watchgod dependency in favour of just relying on uvicorn's dependencies)

[studioswong]

LGTM

[studioswong]

• watchgod 0.8 added support for Python 3.10. At some point we should make kedro-viz support Python 3.9+ (currently it's just up to 3.8, not sure whether there's a reason for that or we just haven't tried out higher version yet).

Good point - I don't see anything stopping us from supporting Python 3.9+, we can definitely look into bumping our python environment up in the setup_python_env and the release_to_pypi steps in our CI files to see if things still work

[limdauto]

The 3.8 pin was only to match Kedro. Don't think we have re-assessed since Kedro moved to 3.9.