Update dependency rstcheck to v6

Author: whitesource-ets[bot]

dev-requirements.txt

@@ -13,7 +13,7 @@ pytest==7.2.0; python_version >= '3'
 # Non-test requirements (python 3+ only)
 pylint==2.5.3; python_version >= '3'
 shellcheck-py==0.9.0.5; python_version >= '3'
-rstcheck==3.5.0; python_version >= '3'
+rstcheck==6.1.2; python_version >= '3'
 yamllint==1.32.0; python_version >= '3'
 voluptuous==0.13.1; python_version >= '3'
 ansible-lint==6.17.0; python_version >= '3.9'