fix: enable Corepack in update-snap-version release job

[mathieuartu]

What

Swap the raw actions/checkout@v4 + actions/setup-node@v4 pair in the update-snap-version job of .github/workflows/create-release-pr.yml for MetaMask/action-checkout-and-setup@v1, matching the pattern this repo's build-lint-test.yml already uses.

Why

Surfaced by #614 (chore: bump Yarn to 4.17.0). The update-snap-version job runs yarn --immutable directly on the runner, but it wasn't enabling Corepack, so it fell back to ubuntu-latest's global Yarn 1.22 and bailed:

error This project's package.json defines "packageManager": "yarn@4.17.0". However the current global version of Yarn is 1.22.22.

The composite action enables Corepack and installs the pinned Yarn 4.17.0, so yarn --immutable resolves the right binary.

Notes

• The first job (create-release-pr) still uses raw actions/checkout + actions/setup-node. It keeps working because MetaMask/action-create-release-pr@v3 self-bootstraps.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud