Revert "Remove unnecessary blank imports (#23283)" (#23302)

This reverts commit 76ad948b80.

server/channels/imports/boards_imports.go

@@ -0,0 +1,9 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package imports
+
+import (
+	// Needed to ensure the init() method in the FocalBoard product is run.
+	_ "github.com/mattermost/mattermost-server/server/v8/boards/product"
+)

server/channels/imports/playbooks_imports.go

@@ -0,0 +1,9 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package imports
+
+import (
+	// Needed to ensure the init() method in the Playbooks product is run.
+	_ "github.com/mattermost/mattermost-server/server/v8/playbooks/product"
+)