bugfix: ghcr container latest tag

[zeroXbrock]

• push 'latest' tag to ghcr in CI release
• chore: update changelogs

Motivation

running docker pull ghcr.io/flashbots/contender:latest would download an old version.

Solution

• tag the image as latest and push it to ghcr

PR Checklist

• Added Tests
• Added Documentation
• Ran cargo +nightly clippy --workspace --lib --examples --tests --benches --all-features --locked --fix
• Ran cargo fmt --all
• Note breaking changes in PR description, if applicable
• update changelogs
  • Update CHANGELOG.md in each affected crate
  • add a high-level description in the root changelog