Upgrade Go toolchain and go-ethereum to address govulncheck advisories

[piotr-roslaniec]

Summary

• CI govulncheck flags multiple stdlib vulnerabilities (GO-2025-4013/4012/4011/4010/4009/4008/4007/3956/3751/3750/3563/3447) on Go 1.22.12.
• go-ethereum v1.10.19 is also flagged (GO-2024-2819). We currently mark govulncheck informational.

Scope

• Raise Go to a patched release (>=1.24.8/1.24.9 once available, or latest LTS with fixes).
• Bump github.com/ethereum/go-ethereum to a fixed version (>=v1.13.15 or newer stable).
• Regenerate code if required, and update any breaking API changes.

Tasks

1. Update actions/setup-go and go.mod/go.sum to the target Go version.
2. Upgrade go-ethereum dependency and fix any compilation changes.
3. Run go mod tidy, go generate ./.../gen (if needed), go vet ./..., go test ./....
4. Re-enable blocking govulncheck (remove continue-on-error) and ensure it passes.
5. Update CHANGELOG.md with the upgrade note.

Acceptance Criteria

• CI green with govulncheck passing without findings.
• Code builds and tests pass on the new Go and go-ethereum versions.
• Changelog documents the upgrades.