leave the repr until we need it

src/_pytest/recwarn.py

@@ -291,6 +291,6 @@ def found_str():
                         fail(
                             f"""\
 DID NOT WARN. No warnings of type {self.expected_warning} matching the regex were emitted.
-The regex is: {self.match_expr!r}
+The regex is: {self.match_expr}
 The list of emitted warnings is: {found_str()}"""
                         )