Bump mypy to 1.8.0 (#113385)

Tools/clinic/clinic.py

@@ -5815,11 +5815,11 @@ class DSLParser:
         parameter_name = parameter.arg
         name, legacy, kwargs = self.parse_converter(parameter.annotation)
 
+        value: object
         if not default:
             if self.parameter_state is ParamState.OPTIONAL:
                 fail(f"Can't have a parameter without a default ({parameter_name!r}) "
                       "after a parameter with a default!")
-            value: Sentinels | Null
             if is_vararg:
                 value = NULL
                 kwargs.setdefault('c_default', "NULL")

Tools/requirements-dev.txt

@@ -1,6 +1,6 @@
 # Requirements file for external linters and checks we run on
 # Tools/clinic, Tools/cases_generator/, and Tools/peg_generator/ in CI
-mypy==1.7.1
+mypy==1.8.0
 
 # needed for peg_generator:
 types-psutil==5.9.5.17