Benchmark action should respect [skip ci]

[Jérémie Astor]

There is no need to benchmark if the commit states to skip the ci.
I think it is just a matter of adding

[ -z $(git log -n1 --oneline --grep='[skip ci]' ] && exit 0

At the beginning of call the other repo step.
See here

[CJ Hewett]

G'Day, could I please work on this issue? Cheers

[Jérémie Astor]

Please do!