migrate some more "OptionalBool" to "Option[bool]" (#29479)

just some refactoring bits towards replacing **util.OptionalBool** with
**optional.Option[bool]**

---------

Co-authored-by: KN4CK3R <admin@oldschoolhack.me>

routers/web/user/notification.go

@@ -17,6 +17,7 @@ import (
 	repo_model "code.gitea.io/gitea/models/repo"
 	"code.gitea.io/gitea/modules/base"
 	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/optional"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/util"
@@ -399,7 +400,7 @@ func NotificationWatching(ctx *context.Context) {
 		OrderBy:            orderBy,
 		Private:            ctx.IsSigned,
 		WatchedByID:        ctx.Doer.ID,
-		Collaborate:        util.OptionalBoolFalse,
+		Collaborate:        optional.Some(false),
 		TopicOnly:          ctx.FormBool("topic"),
 		IncludeDescription: setting.UI.SearchRepoDescription,
 	})