Fix minor doc bot issue (6 lines) (pyccel#1871)

This PR ensures that numpydoc tests are run on `_wrap_X` functions and makes minor
improvements to the associated file by using f-strings instead of join.

Author: EmilyBourne

ci_tools/list_docs_tovalidate.py

@@ -33,9 +33,6 @@ def should_ignore(name):
     #ignore _print_ methods in the codegen.printing module
     if 'Printer._print_' in name:
         return True
-    #ignore _wrap_ methods in the codegen.wrapper module
-    if 'Wrapper._wrap_' in name:
-        return True
     return False
 
 if __name__ == '__main__':
@@ -81,16 +78,16 @@ def should_ignore(name):
                 # inside a function or a class is updated to include
                 # the name of the parent object.
                 if isinstance(node, (FunctionDef, ClassDef)):
-                    if should_ignore('.'.join([prefix, node.name])):
+                    if should_ignore(f'{prefix}.{node.name}'):
                         continue
                     if any((node.lineno <= x <= node.end_lineno
                             for x in line_nos)):
-                        objects.append('.'.join([prefix, node.name]))
+                        objects.append(f'{prefix}.{node.name}')
                     if isinstance(node, ClassDef):
                         obj_pref = node.name
                         for child in node.body:
                             if isinstance(child, (FunctionDef, ClassDef)):
-                                child.name = '.'.join([obj_pref, child.name])
+                                child.name = f'{obj_pref}.{child.name}'
                                 to_visit.append(child)
 
             for obj in objects: