✨ Use sha256 for release hashes

[laurentsimon]

This updates the hash from sha512 to sha256 for release hashes. That's what's expected by the SLSA generator.
sha256 is enough for security

Use sha256 for goreleaser config

[codecov]

Codecov Report

Merging #2172 (83bbd7e) into main (f7c0db7) will increase coverage by 2.40%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main    #2172      +/-   ##
==========================================
+ Coverage   42.27%   44.67%   +2.40%     
==========================================
  Files          95       95              
  Lines        7868     7868              
==========================================
+ Hits         3326     3515     +189     
+ Misses       4282     4086     -196     
- Partials      260      267       +7     

[github-actions]

Integration tests success for
[83bbd7e]
(https://github.com/ossf/scorecard/actions/runs/2885433969)

[naveensrinivasan]

Thanks