Move comment inside relevant section of Python project file

The previous approach of placing the comment before the start of the section caused Poetry to insert items of the
previous section under the comment.

Author: per1234

pyproject.toml

@@ -18,9 +18,9 @@ pytest-mock = "3.10.0"
 flake8 = "5.0.4"
 pep8-naming = "0.13.3"
 
+[tool.poetry.group.external]
 # Provided only for use by boards platforms
 # NOTE: This group is a temporary workaround that will be removed at the 2.0.0 release of the action.
-[tool.poetry.group.external]
 optional = true
 
 [tool.poetry.group.external.dependencies]