Limit CI tests to push events and bump Fjell deps

This release adjusts the CI test triggers and updates Fjell dependencies, alongside setting the package version to 4.4.54.

Continuous Integration

• Run test workflow only on push events (remove pull_request trigger for main) — push triggers remain for main, working, and feature/**; permissions unchanged (commit: "Run test workflow only on push events").

Dependency Updates

• Update dependencies in package.json (commit: "Bump Fjell dependency versions in package.json"):
  • @fjell/core: ^4.4.63 → ^4.4.64
  • @fjell/logging: ^4.4.58 → ^4.4.59
• Update devDependency:
  • @fjell/common-config: ^1.1.30 → ^1.1.31

Versioning

• Set package.json version to 4.4.54 (from 4.4.54-dev.0).