misc: Update GitHub yaml files

This introduces a few fixes to the yaml files, such as fixing
the failing SystemC tests by removing an extra Docker container,
declaring the Python version for our compiler tests, fixing
typos in the GPU daily tests, and adjusting the timeout values
for our compiler tests and unittests.

Change-Id: I3b4f2220750138783717b3678b0d8676155cb2a1
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/71400
Reviewed-by: Bobby Bruce <bbruce@ucdavis.edu>
Maintainer: Bobby Bruce <bbruce@ucdavis.edu>
Tested-by: kokoro <noreply+kokoro@google.com>
Maintainer: Matt Sinclair <mattdsinclair@gmail.com>
Reviewed-by: Matt Sinclair <mattdsinclair@gmail.com>
3 files changed