fix: remove is_vote_valid

[kylezs]

Pull Request

Closes: PRO-1757

Checklist

Please conduct a thorough self-review before opening the PR.

• I am confident that the code works.
• I have written sufficient tests.
• I have written and tested required migrations.
• I have updated documentation where appropriate.

Summary

is_vote_valid was only used once, and was used erroneously. Plus, if a single vote within a group is invalid then the whole extrinsic vails, effectively invalidating all the votes. We have is_vote_needed to prevent engines from submitting too many votes. So have removed it, which simplifies things too. No need to hash the data at all, we can compare the values directly in check_consensus.

[codecov]

Codecov Report

Attention: Patch coverage is 42.85714% with 8 lines in your changes missing coverage. Please review.

Project coverage is 71%. Comparing base (d4eff08) to head (d0727cf).
Report is 8 commits behind head on main.

Files with missing lines	Patch %	Lines
...lections/src/electoral_systems/monotonic_change.rs	43%	7 Missing and 1 partial ⚠️

Additional details and impacted files

@@          Coverage Diff           @@
##            main   #5363    +/-   ##
======================================
  Coverage     71%     71%            
======================================
  Files        495     497     +2     
  Lines      86434   86199   -235     
  Branches   86434   86199   -235     
======================================
- Hits       61703   61544   -159     
+ Misses     21968   21876    -92     
- Partials    2763    2779    +16     

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[dandanlen]

is_vote_needed is currently this:

match current_vote {
			AuthorityVoteOf::<Self>::Vote(current_vote) => current_vote != proposed_vote,
			_ => false,
		}

Should it not be:

match current_vote {
			AuthorityVoteOf::<Self>::Vote(current_vote) => current_vote.value != proposed_vote.value,
			_ => false,
		}

ie. we only want a cote if the value has changed, not if the block has changed?

Otherwise the engines will just vote almost continuously.

[kylezs]

Yeah good point, better that way