CI: Pass branch variable to build jobs.

- CC7 build jobs do not properly identify that the commit matches a tag
- Centos8 and Fedora jobs always identify when the commit matches a tag
- Gitlab-CI may run both a commit and a tag pipeline for the same commit. This creates the unwanted behavior of Centos8 and Fedora building a tag RPM in a commit pipeline

In the end, pass the branch variable from the pipeline to the build script, which now accepts a regex to identify tags