Previously we had generated this via deqp-vk --deqp-runmode=stdout-caselist
+ a sed one-liner to strip off the prefix. Unfortunately, that's not quite
good enough -- that output contains a `GROUP: ` line for every non-leaf in
the the test tree. deqp would then produce log spam when failing to find
those nonexistent tests.

New test list generated by also filtering those `GROUP: ` lines.

Change-Id: If3c97724988f94e2e127e9e091960e1f51e3599a
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/26068Tested-by: Chris Forbes <chrisforbes@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>