[ci] Add OS version to action key in CI
[ci] Add OS version to action key in CI

This commit injects the OS version into a paramter that is used as part
of the action key computation. This should prevent artifacts from
different OS's from colliding in the remote cache.

Signed-off-by: Miles Dai <0447d2cf64f2d947597a59a7749da4cb3bbe9dd1@google.com>

lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan,lowRISC/opentitan