gh-96076: Change test_launcher to use non-admin location for py.ini (GH-96091)

Patch authored by Eryksun.
(cherry picked from commit 216ccac)

Co-authored-by: Terry Jan Reedy <[email protected]>

Author: miss-islington

Lib/test/test_launcher.py

@@ -239,9 +239,11 @@ def run_py(self, args, env=None, allow_fail=False, expect_returncode=0, argv=Non
         return data
 
     def py_ini(self, content):
-        if not self.py_exe:
-            self.py_exe = self.find_py()
-        return PreservePyIni(self.py_exe.with_name("py.ini"), content)
+        local_appdata = os.environ.get("LOCALAPPDATA")
+        if not local_appdata:
+            raise unittest.SkipTest("LOCALAPPDATA environment variable is "
+                                    "missing or empty")
+        return PreservePyIni(Path(local_appdata) / "py.ini", content)
 
     @contextlib.contextmanager
     def script(self, content, encoding="utf-8"):