Update mistune requirement from <2.0 to <3.0 (#70)

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

pyproject.toml

@@ -45,7 +45,7 @@ test = [
 docs = [
 "jinja2",
 "jupyter_server",
-"mistune<2.0",  # https://github.com/jupyter/nbconvert/issues/1685"
+"mistune<3.0",  # https://github.com/jupyter/nbconvert/issues/1685"
 "myst-parser",
 "nbformat",
 "packaging",