cmd/go/testdata/script: restrict test to check only exe name
Avoid test failures caused by 'v2' in user environment paths.
Modify the test to check only the output executable name and ensure it is not 'v2', rather than inspecting the entire path.
Fixes #67989
Change-Id: Ida2131f6c9b41724df1b6b5e31413252c5009d25
Reviewed-on: https://go-review.googlesource.com/c/go/+/621315
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Sam Thanawalla <samthanawalla@google.com> Reviewed-by: Michael Matloob <matloob@golang.org> Reviewed-by: Cherry Mui <cherryyz@google.com> Reviewed-by: Sam Thanawalla <samthanawalla@google.com>