release version v0.12.0

fix(halo/app): fix readiness deadlock (omni-network#2558)

Avoid re-entrant `sync.RWMutex` read locking.

issue: none

ci(scripts/join): fix join nightly eta (omni-network#2300)

Fix zero eta issue.

issue: omni-network#2294

ci(halovisor): use halo v0_8_1 as genesis bin (omni-network#2077)

Use latest release LTS v0.8.1 as halovisor genesis binary.

Also bump cosmovisor for improved logging and error handling.

issue: none

chore(lib/cmd): improve invalid command errors (omni-network#2057)

This will backport the following commits from `main` to `release/v0.8`:
- [chore(lib/cmd): improve invalid command errors
(omni-network#2054)](omni-network#2054)

issue: none

ci(goreleaser): multiarch external releases (omni-network#2021)

This backports the following commits from `main` to `release/v0.8`:
- [ci(goreleaser): multiarch external releases
(omni-network#2008)](omni-network#2008)
- [ci(goreleaser): fix local docker build
(omni-network#2020)](omni-network#2020)

issue: none

ci(github): fix failing release action again (omni-network#1980)

We only support linux/amd64 images at this point.

issue: none

chore(github): push latest halovisor on official release (omni-networ…

…k#1859)

Push (update) `omniops/halovisor:latest` on official release

issue: none

feat(monitor): track validator power and status (omni-network#1821)

Adds basic validator monitoring. Specifically adds a
`monitor_validator_power` metric that maps operator eth address to
consensus eth address and consensus cometBFT address which is required
to map built-in cometBFT validator metrics to our xchain attest
validator metrics.

issue: omni-network#1811

chore(buildinfo): bump version v0_5_0 (omni-network#1734)

Bump version of `release/v0.5` branch

issue: none