fixup: have fake config .getini use correct types

Author: RonnyPfannschmidt

testing/test_junitxml.py

@@ -968,7 +968,7 @@ def __init__(self) -> None:
             self.option = self
             self.stash = Stash()
 
-        def getini(self, name: object) -> str:
+        def getini(self, name: str) -> str:
             return "pytest"
 
         junitprefix = None