test: fix codeigniter.unknownServiceMethod errors

[paulbalandan]

Description
These errors are not phpstan false reports. These are intended for testing purposes thus we can safely locally ignore them.

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

[michalsn]

I'm not sure I understand the benefit of moving these from the baseline file into inline comments.

I get that the baseline is typically used for issues we plan to fix eventually - but filling the source code with a lot of phpstan suppression comments doesn't feel ideal either.

I have mixed feelings about it, but it seems like the right choice for now.

[paulbalandan]

The way I see it:

1. To phpstan baseline - those errors are to be fixed someday. A technical debt for us
2. Inlining - those errors are intended primarily for testing purposes so they are not fixable