[chore] Use pseudo-versions to require `authtest`

[jade-guiton-dd]

Description

Now that #11705 has been merged, splitting the extension/auth/authtest package into a separate module, this PR updates imports of the new module to an externally resolvable pseudo-version based on the merge commit (f2e05b5). (See #11668 for context on why this two-step process is necessary.)

Link to tracking issue

Resolves #11465

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 91.63%. Comparing base (c9f8e8b) to head (3f374d0). Report is 3 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #11724 +/- ## ======================================= Coverage 91.63% 91.63% ======================================= Files 442 442 Lines 23776 23776 ======================================= Hits 21787 21787 Misses 1618 1618 Partials 371 371 ```

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