Plugins: Remove registry dependency from process manager (#73241)

simplify

pkg/plugins/manager/loader/loader_test.go

@@ -23,7 +23,7 @@ import (
 	"github.com/grafana/grafana/pkg/services/org"
 )
 
-var compareOpts = []cmp.Option{cmpopts.IgnoreFields(plugins.Plugin{}, "client", "log"), fsComparer}
+var compareOpts = []cmp.Option{cmpopts.IgnoreFields(plugins.Plugin{}, "client", "log", "mu"), fsComparer}
 
 var fsComparer = cmp.Comparer(func(fs1 plugins.FS, fs2 plugins.FS) bool {
 	fs1Files, err := fs1.Files()