MM-46902: Skip TestFileinfosForPost (#20955)

https://mattermost.atlassian.net/browse/MM-46902

```release-note
NONE
```

api4/post_test.go

@@ -2582,6 +2582,7 @@ func TestSearchPostsWithDateFlags(t *testing.T) {
 }
 
 func TestGetFileInfosForPost(t *testing.T) {
+	t.Skip("MM-46902")
 	th := Setup(t).InitBasic()
 	defer th.TearDown()
 	client := th.Client