Remove dead code identified by deadcode tool (#37271)

Ran [`deadcode`](https://pkg.go.dev/golang.org/x/tools/cmd/deadcode)
(`-test ./...`) to find functions, methods and error types unreachable
from any call path (including tests), and removed the truly-dead ones.

Co-authored-by: Claude (Opus 4.7) <noreply@anthropic.com>

models/organization/team_user.go

@@ -36,14 +36,6 @@ type SearchMembersOptions struct {
 	TeamID int64
 }
 
-func (opts SearchMembersOptions) ToConds() builder.Cond {
-	cond := builder.NewCond()
-	if opts.TeamID > 0 {
-		cond = cond.And(builder.Eq{"": opts.TeamID})
-	}
-	return cond
-}
-
 // GetTeamMembers returns all members in given team of organization.
 func GetTeamMembers(ctx context.Context, opts *SearchMembersOptions) ([]*user_model.User, error) {
 	var members []*user_model.User