removed myst-parser pin from RTD conda env

The historical pin of myst-parser=~1.0 prevents modern sphinx>=7 and fails on RTD.
Letting myst-parser to float freely does not affect local builds.
The package is not listed in pyproject.toml so should not adversely affect downstream users.

Author: orbeckst

docs/environment.yml

@@ -14,7 +14,7 @@ dependencies:
   - nbconvert
   - ipykernel
   - autodoc-pydantic
-  - myst-parser~=1.0
+  - myst-parser
   - pandoc
   - wheel
   - sphinx-autobuild