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>
(cherry picked from commit f6656181e4a07d6c415927220efa2077d509f7c6)

Conflicts:
	models/repo/repo_list_test.go
	trivial shared fixture count conflicts

routers/api/v1/repo/issue.go

@@ -20,6 +20,7 @@ import (
 	"code.gitea.io/gitea/models/unit"
 	user_model "code.gitea.io/gitea/models/user"
 	issue_indexer "code.gitea.io/gitea/modules/indexer/issues"
+	"code.gitea.io/gitea/modules/optional"
 	"code.gitea.io/gitea/modules/setting"
 	api "code.gitea.io/gitea/modules/structs"
 	"code.gitea.io/gitea/modules/timeutil"
@@ -143,7 +144,7 @@ func SearchIssues(ctx *context.APIContext) {
 			Private:     false,
 			AllPublic:   true,
 			TopicOnly:   false,
-			Collaborate: util.OptionalBoolNone,
+			Collaborate: optional.None[bool](),
 			// This needs to be a column that is not nil in fixtures or
 			// MySQL will return different results when sorting by null in some cases
 			OrderBy: db.SearchOrderByAlphabetically,
@@ -166,7 +167,7 @@ func SearchIssues(ctx *context.APIContext) {
 			opts.OwnerID = owner.ID
 			opts.AllLimited = false
 			opts.AllPublic = false
-			opts.Collaborate = util.OptionalBoolFalse
+			opts.Collaborate = optional.Some(false)
 		}
 		if ctx.FormString("team") != "" {
 			if ctx.FormString("owner") == "" {