Update GitHub Actions runtimes

[mre]

Summary

• update checkout to the Node.js 24-based v7 release in both workflows
• update Wrangler Action to v4, which uses Node.js 24
• update create-issue-from-file to its Node.js 24-based v6 release
• replace the mutable Lychee master ref with the maintained v2 tag

Validation

• parsed both workflow files as YAML
• ran git diff --check
• verified the updated JavaScript actions declare the Node.js 24 runtime

The Cloudflare deployment step remains restricted to master, so pull request CI validates the build but intentionally skips deployment.