gitlab: Only run CI in main and coverage branches
gitlab: Only run CI in main and coverage branches

This workflow rule will prevent this CI config from running unless the
branch name is "main" or "coverage".  It will have to be cherry-picked
into all the other branches to make them stop running sadly.

BRANCH=None
BUG=b:244766499
TEST=Used yaml validator at
https://gitlab.com/zephyr-ec/ec/-/ci/editor?branch_name=main&tab=2

Signed-off-by: Jeremy Bettis <4df7b5147fee087dca33c181f288ee7dbf56e022@google.com>
Change-Id: I536de3e3fdbca1c48505e61de5737f865bd0e233
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3872545
Reviewed-by: Simon Glass <c00b0378376498bd9cd974c388df8854c0131d27@chromium.org>
Tested-by: Jeremy Bettis <4df7b5147fee087dca33c181f288ee7dbf56e022@chromium.org>
Commit-Queue: Simon Glass <c00b0378376498bd9cd974c388df8854c0131d27@chromium.org>
Auto-Submit: Jeremy Bettis <4df7b5147fee087dca33c181f288ee7dbf56e022@chromium.org>
Commit-Queue: Jeremy Bettis <4df7b5147fee087dca33c181f288ee7dbf56e022@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec