[23.1] Only reindex tool search once after forking

[mvdbeek]

Makes forking new workers with gunicorns --max-requests setting more efficient ... and anyway no point in doing this more than once.

How to test the changes?

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• I've included appropriate automated tests.
• This is a refactoring of components with existing test coverage.
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  1. [add testing steps and prerequisites here if you didn't write automated tests covering all your changes]

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