Log Message:
py-nbconvert: updated to 6.5.0

6.5.0
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* Support bleach 5, add packaging and tinycss2 dependencies by @bollwyvl
* Drop dependency on testpath. by @anntzer
* Adopt pre-commit by @blink1073
* Add pytest settings and handle warnings by @blink1073
* Update cli example by @leahecole
* Clean up workflows by @blink1073