chore(deps): update dependency sphinx to v6 (#215)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

requirements_doc.txt

@@ -1,2 +1,2 @@
-Sphinx==5.3.0
+Sphinx==6.0.0
 sphinx-rtd-theme==1.1.1