Bump sphinx-rtd-theme from 1.2.2 to 1.3.0 in /docs/readthedocs (#866)

Author: dependabot[bot]

docs/readthedocs/requirements.txt

@@ -1,6 +1,6 @@
 commonmark==0.9.1
 recommonmark==0.7.1
 Sphinx==6.2.1
-sphinx-rtd-theme==1.2.2
+sphinx-rtd-theme==1.3.0
 myst-parser==2.0.0
 markdown-it-py==3.0.0