gh-37726: sage-bootstrap: update cryptographic hashes
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Update cryptographic hashes to use sha256 instead of sha1 due to
insecurity of sha1.
- Fixes #37691
- Fixes #37558, see also
https://github.com/sagemath/sage/pull/36677#issuecomment-2041279554
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### :hourglass: Dependencies
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- #37570
- #37249
- #37914
URL: https://github.com/sagemath/sage/pull/37726
Reported by: Faisal
Reviewer(s): Matthias Köppe, roed314
