test: let fake_getpwuid return pwd.struct_passwd

`pwd.getpwuid` returns a `pwd.struct_passwd`. So let `fake_getpwuid`
return the same type.

Signed-off-by: Benjamin Drung <benjamin.drung@canonical.com>

tests/integration/test_ui.py

@@ -1582,10 +1582,10 @@ def test_run_crash_anonymity_escaping(self):
         orig_getpwuid = pwd.getpwuid
         orig_getuid = os.getuid
 
-        def fake_getpwuid(_unused_uid):
+        def fake_getpwuid(_unused_uid: int) -> pwd.struct_passwd:
             r = list(orig_getpwuid(orig_getuid()))
             r[4] = "Joe (Hacker,+1 234,,"
-            return r
+            return pwd.struct_passwd(r)
 
         pwd.getpwuid = fake_getpwuid
         os.getuid = lambda: 1234