When using release-please on GitHub enterprise, some links at changelog/release points to github

## Description

When using release-please-action v4 on github enterprise (e.g https://self-host.github.example.com), changelog-host needs to be configured in release-please-config, or else some links in changelog.md and releases will point to github.com

By default i expect github enterprise to have correct links without extra configuration.

#### Environment details

- OS:
- Node.js version:
- npm version:
- `release-please` version: 16.12.0 (release-please-action)

#### Steps to reproduce

1. ?
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Making sure to follow these steps will guarantee the quickest resolution possible.

Thanks!