Update gdscript_styleguide.rst - clarified sentence and grammar (#9110)

* Update gdscript_styleguide.rst - clarified sentence and grammar

- Clarified the statement on "One statement per line"
- Removed unclear sentence with incorrect grammar

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Co-authored-by: A Thousand Ships <96648715+AThousandShips@users.noreply.github.com>

tutorials/scripting/gdscript/gdscript_styleguide.rst

@@ -307,8 +307,8 @@ editor. For example, when looking at a differential revision.
 One statement per line
 ~~~~~~~~~~~~~~~~~~~~~~
 
-Never combine multiple statements on a single line. No, C programmers,
-not even with a single line conditional statement.
+Avoid combining multiple statements on a single line, including conditional
+statements, to adhere to the GDScript style guidelines for readability.
 
 **Good**: