⬆️ Update myst-parser requirement from <4,>=2 to >=2,<5

Updates the requirements on [myst-parser](https://github.com/executablebooks/MyST-Parser) to permit the latest version.
- [Release notes](https://github.com/executablebooks/MyST-Parser/releases)
- [Changelog](https://github.com/executablebooks/MyST-Parser/blob/master/CHANGELOG.md)
- [Commits](executablebooks/MyST-Parser@v2.0.0...v4.0.0)

---
updated-dependencies:
- dependency-name: myst-parser
  dependency-type: direct:production
...

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

pyproject.toml

@@ -36,9 +36,9 @@ Documentation = "https://sphinx-design.readthedocs.io"
 
 [project.optional-dependencies]
 code-style = ["pre-commit>=3,<4"]
-rtd = ["myst-parser>=2,<4"]
+rtd = ["myst-parser>=2,<5"]
 testing = [
-    "myst-parser>=2,<4",
+    "myst-parser>=2,<5",
     "pytest~=8.3",
     "pytest-cov",
     "pytest-regressions",