Handle github merge-queue better?

[teads-pierre-sabouret]

On Github merge-queue, nrwl/nx-set-shas takes the parent commit as base.

let's assume there are 2 PR in the MQ, PR-A & PR-B.
PR-A modifies package-1 & PR-B modify package-2.

MQ will run on PR-A
And then on PR-B rebased on PR-A.

On both of these runs, I expect package-1 & package-2 to be affected. Because the cache for package-1 & package-2 will probably get written in the master workflow as "stable".

I would then set the base-sha as master instead of "parent commit."

WDYT?

[JamesHenry]

@teads-pierre-sabouret I haven't personally used GitHub merge queues, would you please be able to set up a minimal example repo that we can collaborate on?

[Simon-Leslie]

@JamesHenry merge queues are unavailable on private repos but hopefully my PR linked above helps explain the situation