Parametrize links in docs to point at the correct branch

[ppalaga]

When the docs references the quarkus-cxf-integration-tests or similar, we point to the same branch as the current docs stream - i.e. 3.8 docs should point to https://github.com/quarkiverse/quarkus-cxf/tree/3.8

[ppalaga]

We already have an attribute for that around here: https://github.com/quarkiverse/quarkus-cxf/blob/3.8/docs/antora.yml#L23