[MM-17889] Implement validation of plugin API version comments (#11941)

plugin/checker/test/missing/missing.go

@@ -0,0 +1,8 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package missing
+
+// SomeType is a fake interface for testing the plugin comment checker.
+type SomeType interface {
+}