fix: Model::_call() static analysis

[kenjis]

Description
Fixes #4509

• remove @mixin BaseBuilder, add @method

Checklist:

• Securely signed commits
• Component(s) with PHPDoc blocks, only if necessary or adds value
• [] Unit testing, with >80% coverage
• [] User guide updated
• Conforms to style guide

[MGatner]

I'm sad that dynamic extensions didn't work out (but grateful you tried it). This looks like an improvement, and it already allowed SA to detect a mistake!

[kenjis]

It might be my misunderstanding that the dynamic extensions didn't work out.
But the true problem is not sure what methods really can be used.
I mean, it was later discovered that getCompiled*() could not be used after all.
The current implementation can call all Builder methods, but not sure if that will actually work well.

It would be better to add really usable methods to @method.