[Chapel Merge] Update some links to refer to renamed main branch

Branch: refs/heads/main
Revision: c030f12
Author: bmcdonald3
Link: Update some links to refer to renamed main branch by bmcdonald3 · Pull Request #19707 · chapel-lang/chapel · GitHub
Log Message:

Merge pull request #19707 from bmcdonald3/update-links

Update some links to refer to renamed main branch

There were some links that were referring to outdated branch names in Chapel, so this updates them to refer to main instead, which is the new name.

[ trivial, not reviewed ]

Modified Files:
M test/release/examples/primers/interopWithC.chpl

M third-party/qthread/qthread-src/test/benchmarks/generic/time_thread_ring.c

Compare: https://github.com/chapel-lang/chapel/compare/d523d0f3b383...c030f121b14c