Enable unparam linter and fix reported errors

What does this MR do?

Enables the unparam linter and fixes the reported issues.

Why was this MR needed?

To make our reviews quicker and more thorough by automatically detecting unnecessary parameters/return values.

Are there points in the code the reviewer needs to double check?

• Some test helpers were receiving unused parameters, however I feel that not passing those parameters to the function makes it clearer to the caller which values actually play a role (e.g. in a method that sets up a mock).

Does this MR meet the acceptance criteria?

• Documentation created/updated
• Added tests for this feature/bug
• In case of conflicts with master - branch was rebased

What are the relevant issue numbers?

Closes #25166 (closed)