tests,misc: Updated presubmit YAML to use main.py '-t' flag
This minor change reduces the presubmit build time by about 10 to 15
minutes.
Change-Id: I3a87d1a720b17fd22a9dbdbeebfb32e4be178c56
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/27064
Tested-by: Gem5 Cloud Project GCB service account <345032938727@cloudbuild.gserviceaccount.com>
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Gabe Black <gabeblack@google.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>