Directives in namespaces collected via RegisterDirectiveNamespaces no longer override default directives

[tminich]

Describe the bug

Overriding default directives in a namespace collected by the RegisterDirectiveNamespaces event used to override default directives in lighthouse 5.x, this no longer works in 6.x

Expected behavior/Solution

This is in reply/reference to #2396
I used to override default directives in a module by defining them and returning the namespace via RegisterDirectiveNamespaces but this stopped working in 6.x. Hence I tried rebinding via the Laravel container system, which worked, beside the issue described in #2396, flawlessly. So I assumed this was now the intended way.
At the end of the day I can do it either way, but I need a way that works for everything =)

Steps to reproduce

1. Define a directive supposed to override a default directive in a namespace (eg. EnumDirective)
2. Directive isn't overridden, neither functionally nor in documentation
   or
3. Use container binding to override a default directive
4. Directive is overridden functionally but not in documentation

Lighthouse Version

6.9.0

[spawnia]

I think this behaviour change was introduced in #2337. I am working on a fix.