Reset datafetcher references in teardown

[ananthsub]

What does this PR do?

Very similar to #9386. While the data connector calls the teardown, it doesn't actually reset these, which can be an issue because of the references the data fetcher itself holds

Does your PR introduce any breaking changes? If yes, please list them.

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[tchaton]

LGTM !

[codecov]

Codecov Report

Merging #9387 (eea9530) into master (83bff01) will decrease coverage by 4%.
The diff coverage is 100%.

❗ Current head eea9530 differs from pull request most recent head 0473767. Consider uploading reports for the commit 0473767 to get more accurate results

@@           Coverage Diff           @@
##           master   #9387    +/-   ##
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- Coverage      93%     89%    -4%     
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  Files         180     179     -1     
  Lines       15062   14931   -131     
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- Hits        13983   13259   -724     
- Misses       1079    1672   +593