minor #42490 More return type fixes (bis) (nicolas-grekas)

This PR was merged into the 5.4 branch.

Discussion
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More return type fixes (bis)

| Q             | A
| ------------- | ---
| Branch?       | 5.4
| Bug fix?      | no
| New feature?  | no
| Deprecations? | no
| Tickets       | -
| License       | MIT
| Doc PR        | -

Commits
-------

c6a20b4e4d More return type fixes (bis)

Author: nicolas-grekas

Tests/Mapping/MemberMetadataTest.php

@@ -112,7 +112,7 @@ public function getPropertyValue($object)
     {
     }
 
-    protected function newReflectionMember($object): object
+    protected function newReflectionMember($object): \ReflectionMethod
     {
     }
 }