Add missing closing quote and trailing period in str.isidentifier() docstring (GH-9756)

This rectifies commit ffc5a14.

Author: lelit

Objects/clinic/unicodeobject.c.h

@@ -12101,12 +12101,12 @@ str.isidentifier as unicode_isidentifier
 Return True if the string is a valid Python identifier, False otherwise.
 
 Call keyword.iskeyword(s) to test whether string s is a reserved identifier,
-such as "def" or "class
+such as "def" or "class".
 [clinic start generated code]*/
 
 static PyObject *
 unicode_isidentifier_impl(PyObject *self)
-/*[clinic end generated code: output=fe585a9666572905 input=2fb643aafbcf0e1c]*/
+/*[clinic end generated code: output=fe585a9666572905 input=2d807a104f21c0c5]*/
 {
     return PyBool_FromLong(PyUnicode_IsIdentifier(self));
 }