MM-22355 - Fix typos detected by goreportcad.com (#13842)

* Update webhook_test.go

* Update user_test.go

* Update filesstore_test.go

* Update plugin_requests.go

* Update syncables.go

* Update helper.go

* Update html_entities.go

* Update user.go

* Update team.go

* Update notification.go

* Update notification_test.go

* Update plugin_api_test.go

* Update post_metadata.go

* Update channel_test.go

* Update database.go

* Update channel.go

* Update user_store.go

* Update team_test.go

* revert andd

* Revert back to infintie

Co-authored-by: Jesús Espino <jespinog@gmail.com>
Co-authored-by: mattermod <mattermod@users.noreply.github.com>

app/notification_test.go

@@ -247,7 +247,7 @@ func TestFilterOutOfChannelMentions(t *testing.T) {
 		assert.Nil(t, outOfGroupUsers)
 	})
 
-	t.Run("should not return results for non-existant users", func(t *testing.T) {
+	t.Run("should not return results for non-existent users", func(t *testing.T) {
 		post := &model.Post{}
 		potentialMentions := []string{"foo", "bar"}