Fix config issue

[dasha-shchep]

Closes #107.

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PR creation checklist for the reviewer

• Does the feature branch name follow the format <issue_number>_<short_description_of_feature>?
• Does the PR title exactly match with the issue title?
• Have appropriate reviewers been added to the PR (once it is ready for review)?
• Has the PR been assigned to the developer?
• Has the Climate Model Evaluation Workflow (CMEW) project been added to the PR?
• Has the appropriate milestone been added to the PR?

Definition of Done for the reviewer

• Does the change in this PR address the above issue / have all acceptance criteria been met?
• Does the change in this PR follow the recommendations in the wiki: Developer Guide?
• Have new tests related to the change been added?
• Do all the GitHub workflow checks pass?
• Do all the tests run locally and pass? (Note: the tests are not run by the GitHub workflow, see wiki: Run the tests locally)
• Has the API documentation related to the change been updated appropriately?
• Has the user documentation related to the change been updated appropriately?
• Do the HTML pages render correctly? (See wiki: Build the documentation locally)
• Do the steps in the Quick Start section of the documentation work?

[mo-nabilbrice]

The change follows exactly from the Python API changelog in the ESMValTool documentation.

The configure_process test is now passing.

[ehogan]

Thank you for fixing this bug @dasha-shchep! 🥳

I would be happy for you to tick the adding / updating any new tests / documentation boxes, since the current tests cover this change, and there are no related documentation changes 😊

Please also mark this PR as "Ready for review" so it can be merged 😊

I also wanted to add explicitly to this PR that the process_radiation_budget task now fails, but this issue will be addressed via #114.