Github tasks fail when using github enterprise

[dcinzona]

Describe the bug

BaseGithubTask is used as the inherited class for github tasks. This task only checks for services of type "github" and does not check for github_enterprise services.
When working in environments that use enterprise GH, a lot of the packaging functionality doesn't work as this raises an exception.

Reproduction steps

1. Configure a github_enterprise service (and no github service)
2. Run cci flow run release_unlocked_beta

Your CumulusCI and Python versions

CumulusCI version: 3.89.0
Python version: 3.12.1

Operating System

MacOS

Windows environment

No response

CumulusCI installation method

pipx

Error Gist

No response

Additional information

I have a fork with a branch and fix ready for review. Would need a branch to be able to create a PR