MM-64438: skip flaky: testGetNthRecentPostTime (#31223)

server/channels/store/storetest/post_store.go

@@ -5279,6 +5279,8 @@ func getPostIds(posts []*model.Post, morePosts ...*model.Post) []string {
 }
 
 func testGetNthRecentPostTime(t *testing.T, rctx request.CTX, ss store.Store) {
+	t.Skip("https://mattermost.atlassian.net/browse/MM-64438")
+
 	_, err := ss.Post().GetNthRecentPostTime(0)
 	assert.Error(t, err)
 	_, err = ss.Post().GetNthRecentPostTime(-1)