ci: migrate Catalyst workflows to Taiko

[davidtaikocha]

Summary

• Consolidate Rust formatting, Clippy, spelling, tests, and dependency policy checks into one Taiko-owned CI workflow on GitHub-hosted runners.
• Replace the Nethermind-gated image workflows with a main-node-only Docker workflow for us-docker.pkg.dev/evmchain/images/catalyst-node.
• Validate Docker builds without credentials on pull requests; publish native linux/amd64 and linux/arm64 images by digest and merge them into one manifest on master and v* tags.
• Authenticate GAR publishing with Taiko's existing GitHub OIDC / Workload Identity Federation setup.
• Retire legacy node, P2P, spammer, pytest-old, and split Rust workflows while leaving the existing E2E and Claude workflows unchanged.
• Make BLST_PORTABLE an effective Docker build argument and update Cargo.lock to patched anyhow, crossbeam-epoch, and ruint releases required by the dependency audit.

Validation

• cargo fmt --all -- --check
• cargo clippy --workspace --all-features --exclude p2p-boot-node --locked -- -D warnings
• cargo test --workspace --locked --verbose (129 unit tests plus doc tests)
• typos .
• cargo deny check (passes; retains one existing transitive yanked spin 0.9.8 warning)
• actionlint .github/workflows/*.yml
• docker buildx build --call=check --file Dockerfile .
• Local CI migration contract and staged diff checks

Before merge

• Confirm the pull-request Docker validation job completes. Two local full-build attempts reached the container's Optimism git dependency fetch and made no further progress; they were cancelled without a compile failure.
• Confirm the WIF provider permits taikoxyz/Catalyst and gar-github-action@evmchain.iam.gserviceaccount.com can write us-docker.pkg.dev/evmchain/images/catalyst-node.