Secure URL now fatal errors due to having a string return type

[SOD96]

Laravel Version

12.3.1

PHP Version

8.3

Database Driver & Version

MySQL 8

Description

Secure URL now requires a string be returned, despite allowing a null path to be passed in, which results in a different type being returned (URLGenerator)

I believe this PR was responsible: #56684

Steps To Reproduce

I've actually had to resolve this in another project which uses the helper functions from Laravel -> ralphjsmit/laravel-seo#100

[crynobone]

Fixed via #56807