llvmbot monitor: Restrict builds list to main branch
We used to ask for all builds and filter from there, but now
that pre-commit llvm PRs are doing many more builds, we aren't
finding a finished main build in the 100 entries we get back
by default.
Instead of filtering afterwards, change the initial query to be
main only.
It's still possible there would be 100 builds without a finished
one, but if that ever happens we can make use of the pagination
feature to get more until we find one.
Change-Id: Ia9e5d090ad86c8257b14be0a2dd81f1237b9233a
1 file changed