MM-45208: strip post meta for plugins (#20686)

Try two...

* Revert "Revert "Removed the opengraph type dependency for plugins by stripping post Metadata (#20612)" (#20684)"

This reverts commit 32dee6d449.

* Fixed race condition

* PR feedback

* lint

plugin/client_rpc.go

@@ -21,7 +21,6 @@ import (
 	"reflect"
 	"sync"
 
-	"github.com/dyatlov/go-opengraph/opengraph"
 	"github.com/go-sql-driver/mysql"
 	"github.com/hashicorp/go-plugin"
 	"github.com/lib/pq"
@@ -164,7 +163,6 @@ func init() {
 	gob.Register(&pq.Error{})
 	gob.Register(&mysql.MySQLError{})
 	gob.Register(&ErrorString{})
-	gob.Register(&opengraph.OpenGraph{})
 	gob.Register(&model.AutocompleteDynamicListArg{})
 	gob.Register(&model.AutocompleteStaticListArg{})
 	gob.Register(&model.AutocompleteTextArg{})