Change how SPO votes are counted

[Lucsanszky]

Description

Resolves #4645

Checklist

• [x] Commit sequence broadly makes sense and commits have useful messages
• [x] New tests are added if needed and existing tests are updated
• [x] All visible changes are prepended to the latest section of a CHANGELOG.md for the affected packages. New section is never added with the code changes. (See RELEASING.md)
• [ ] When applicable, versions are updated in .cabal and CHANGELOG.md files according to the versioning process.
• [ ] The version bounds in .cabal files for all affected packages are updated. If you change the bounds in a cabal file, that package itself must have a version increase. (See RELEASING.md)
• [x] Code is formatted with fourmolu (use scripts/fourmolize.sh)
• [x] Cabal files are formatted (use scripts/cabal-format.sh)
• [x] hie.yaml has been updated (use scripts/gen-hie.sh)
• [x] Self-reviewed the diff

[Lucsanszky]

~I had to disable the ratify conformance test until https://github.com/IntersectMBO/formal-ledger-specifications/issues/578 is resolved, since now the spec and the implementation differs with regards to the SPO vote counts.~ I managed to tweak the SPO votes for conformance tests to make the tests pass until the spec is up-to-date. I'll probably add some more comments why I needed to adjust some of the stake amounts in pools for the tests (electBasicCommittee registers a stake pool and with the vote count changes we didn't always reach the threshold post-bootstrap). Other than that, this is ready for review and I'll add some tests in a separate PR.

[Lucsanszky]

This looks great! We'll definitely need to a few Imp tests for this and re-enable RATIFY conformance test once spec catches up. But, it is definitely OK to postpone that work until after this PR is merged.

Sounds good! I managed to tweak the conformance tests to filter for Abstain votes for SPOs, which is slightly better than disabling the RATIFY conformance tests altogether.