test: add wait time after DOI creation

[candleindark]

To avoid the behavior of the bug documented at datacite/datacite#2307 so that our test servers are not populated with undeletable DOIs.

This PR implements the first option of the three listed below to address the the behavior of the bug documented at datacite/datacite#2307. If undeletable DOIs continue to occur after this PR is applied. We should consider implementing another option instead.

1. Insert a waiting period of about 1-2 seconds between the creation and deletion of the same DOI. (This solution is not perfect since a GH Action job that is running such a test can get cancelled just after the creation of a DOI, and a created DOI may not be deleted. However, the situation of a created DOI that is not eventually deleted is unlikely, and this solution ensures that a created DOI can always be deleted. You may just need to delete some of them manually).
2. Have the tests only create DOIs but not delete them, and run another CI job to delete the DOIs created by the tests periodically. This approach also ensure the created DOIs are deletable. However, those DOIs will remain in the server for a period of time.
3. Implement option 1 but also a CI job to periodically remove any created DOIs that have not been deleted.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 97.89%. Comparing base (cabfa3d) to head (27383c6).
⚠️ Report is 2 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #363   +/-   ##
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  Coverage   97.89%   97.89%           
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  Files          18       18           
  Lines        2377     2379    +2     
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+ Hits         2327     2329    +2     
  Misses         50       50           

Flag	Coverage Δ
unittests	97.89% <100.00%> (+<0.01%)	⬆️

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[Copilot]

Pull request overview

This PR adds a 3-second wait after DOI creation in the test suite to work around a DataCite API bug that can result in undeletable DOIs on test servers.

Changes:

• Added a sleep(3) call after DOI creation to allow DataCite to properly process the DOI before attempting subsequent operations

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[candleindark]

@sandyhider Please let use know if you continue to see undeletable DOIs continue to be created after this PR is applied.

[yarikoptic]

let's see if helps?!