Add gov/proposals/roots/v0 namespace

[joaosreis]

No description provided.

[joaosreis]

IntersectMBO/cardano-ledger#5747 was approved, so this one is good to go as well

[Copilot]

Pull request overview

This PR adds support for the new gov/proposals/roots/v0 SCLS namespace, wiring it into the schema registry, conformance tests, and reference CDDL loading, while bumping the pinned CIP-0165 source revision used in CI/Nix.

Changes:

• Introduce Cardano.SCLS.Namespace.GovProposalsRoots and register gov/proposals/roots/v0 in Cardano.SCLS.CDDL (KnownSpec, namespace list, key size).
• Extend test utilities and reference CDDL mapping to include gov/proposals/roots/v0.
• Update the pinned tweag/CIPs revision in Nix + CI and relocate gov_action_id into Cardano.SCLS.Common for reuse.

Reviewed changes

Copilot reviewed 9 out of 10 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
scls-cardano/testlib/Cardano/SCLS/Testlib.hs	Adds the new namespace to the conformance test runner.
scls-cardano/test/Reference.hs	Adds reference CDDL filename mapping for gov/proposals/roots/v0.
scls-cardano/scls-cardano.cabal	Registers the new namespace module in the library build.
scls-cardano/cddl-src/Cardano/SCLS/Namespace/GovProposalsRoots.hs	New schema module defining the namespace’s record_entry.
scls-cardano/cddl-src/Cardano/SCLS/Namespace/GovProposals.hs	Removes the local gov_action_id rule (now shared from Common).
scls-cardano/cddl-src/Cardano/SCLS/Common.hs	Adds shared gov_action_id rule.
scls-cardano/cddl-src/Cardano/SCLS/CDDL.hs	Registers KnownSpec + key size + knownNamespaces entry for the new namespace.
flake.nix	Bumps pinned tweag/CIPs revision.
flake.lock	Updates lock data for the bumped tweag/CIPs revision.
.github/workflows/haskell-ci.yml	Updates CI checkout ref for tweag/CIPs to match the new revision.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[qnikst]

Looks good to me, modulo Copilot and mine comment! Free to merge after checking those comments