Use a custom regex for changelog tags

What does this MR do?

The tag format we use for gitlab-org/gitlab doesn't follow semantic versioning; at least not as we expected. The -ee suffix we use for tags is treated as the pre-release identifier, and when generating changelogs we ignore pre-release tags. To solve this we need a custom tag regex to ignore the -ee suffix.

See gitlab-com/gl-infra/delivery#1776 (closed) for more information.

This fixes #331862, gitlab-com/gl-infra/delivery#1776 (closed)

Does this MR meet the acceptance criteria?

Conformity

• I have self-reviewed this MR per code review guidelines.
• This MR does not harm performance, or I have asked a reviewer to help assess the performance impact. (Merge request performance guidelines)
• I have followed the style guides.