Hotfix/v0.1.3

[0ngk]

This pull request makes improvements to the release workflow and updates the example manifest. The most significant changes are enhancements to the publish job's reliability and error reporting, as well as a version bump for a local dependency in the example project.

Workflow improvements:

• The publish job in .github/workflows/gleam-bootstrap.yml now runs on ubuntu-latest instead of ubuntu-24.04, and specifies the release environment for better environment management.
• Added a shell script in the publish step to check if the HEXPM_API_KEY secret is configured before publishing. This provides clearer error messages and safer execution by failing early if the secret is missing.

Example manifest update:

• Updated the kitazith dependency in examples/kitazith_example/manifest.toml from version 0.1.2 to 0.1.3 to use the latest local changes.