Make the buildbot aware of the configuration templates

Summary:
Tha buildbot a lacking the feature, which causes it to not run all the
builds on diff.

Test Plan:
Submit a diff with a C++ change and check the builds are run as
expected.

Reviewers: #bitcoin_abc, jasonbcox

Reviewed By: #bitcoin_abc, jasonbcox

Differential Revision: https://reviews.bitcoinabc.org/D8520