Use regex to properly select Go test runnable (#13750)
Connor Finnell
created
This is already done when selecting a subtest; by wrapping the test name
with `^{}$` the runnable will avoid selecting additional tests with the
same prefix.
Without this fix, selecting the runnable for `TestExample` will also run
`TestExample2`.
Release Notes:
- Fixed Golang tasks spawning tests starting with the current function name and not using the exact match.