After https://github.com/10gen/mongo/pull/27249 merged the coverage variant should be generating gcno profile files from Bazel targets. It sounds like the coverage collection script needs to be updated to pick them up during the time when we have Bazel targets and SCons test targets

We're estimating to start converting test targets to Bazel in a little over a month, but we'll likely shard out the work so it may take a few months for all test targets to be converted to Bazel.