Update sphinx-rtd-theme requirement from <1.3,>=0.4.3 to >=0.4.3,<1.4

Updates the requirements on [sphinx-rtd-theme](https://github.com/readthedocs/sphinx_rtd_theme) to permit the latest version.
- [Changelog](https://github.com/readthedocs/sphinx_rtd_theme/blob/master/docs/changelog.rst)
- [Commits](readthedocs/sphinx_rtd_theme@0.4.3...1.3.0)

---
updated-dependencies:
- dependency-name: sphinx-rtd-theme
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

pyproject.toml

@@ -53,7 +53,7 @@ doc = [
     "myst-nb>=0.13.2,<0.18",
     "sphinx>=5.2.0,<7.3",
     "sphinxcontrib-httpdomain>=1.7.0,<1.9",
-    "sphinx_rtd_theme>=0.4.3,<1.3"
+    "sphinx_rtd_theme>=0.4.3,<1.4"
 ]
 test = [
     "coverage>=4.5.3,<7.3",