fix(deps): update sphinx-rtd-theme requirement from <3,>=1 to >=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@1.0.0...3.0.0)

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

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

Author: dependabot[bot]

pyproject.toml

@@ -13,7 +13,7 @@ license = {file = "LICENSE"}
 urls = {homepage = "https://github.com/centralnicgroup-opensource/rtldev-middleware-python-sdk/"}
 dependencies = [
     "docutils>=0,<1",
-    "sphinx-rtd-theme>=1,<3",
+    "sphinx-rtd-theme>=1,<4",
     "m2r2>=0,<1",
     "pytest-cov>=2,<6",
     "sphinx>=3,<9",