Plugins: Simplify plugin file removal (#66115)

* make explicit class check when attempting to remove plugin

* simplify plugin file tracking

* fix test

* apply feedback

* fix linter

pkg/plugins/ifaces.go

@@ -58,6 +58,10 @@ type FS interface {
 	Files() []string
 }
 
+type FSRemover interface {
+	Remove() error
+}
+
 type FoundBundle struct {
 	Primary  FoundPlugin
 	Children []*FoundPlugin