functions: remove unused setting_ module variables (#1475)

A tiny cleanup in line with the recommendation I pushed to @CodesAway's
#1474.

With the move to `settings.get()`, we should no longer assign settings
to module-level variables, since it's no longer needed, and we don't
want anyone to use them by mistake. These aren't being used, so let's
just remove them.

This means you can now grep for `= mod.setting(` to search for old
usages, and it comes up clean on main.

(To my surprise, this code was using `settings.get()` from the beginning
when @wenkokke wrote it)

lang/tags/functions.py

@@ -32,16 +32,12 @@ def code_type(m) -> str:
     return m.code_type
 
 
-setting_private_function_formatter = mod.setting("code_private_function_formatter", str)
-setting_protected_function_formatter = mod.setting(
-    "code_protected_function_formatter", str
-)
-setting_public_function_formatter = mod.setting("code_public_function_formatter", str)
-setting_private_variable_formatter = mod.setting("code_private_variable_formatter", str)
-setting_protected_variable_formatter = mod.setting(
-    "code_protected_variable_formatter", str
-)
-setting_public_variable_formatter = mod.setting("code_public_variable_formatter", str)
+mod.setting("code_private_function_formatter", str)
+mod.setting("code_protected_function_formatter", str)
+mod.setting("code_public_function_formatter", str)
+mod.setting("code_private_variable_formatter", str)
+mod.setting("code_protected_variable_formatter", str)
+mod.setting("code_public_variable_formatter", str)
 
 
 @mod.action_class