Make `tezos-client-typecheck` stage in CI not run on every commit for every merge request
Clarification and motivation
tezos-client-typecheck
stage in CI previously usually took 1-2 minutes, but now it takes 6+ minutes, which is annoying.
Let's run it nightly every day or something.
Acceptance criteria
tezos-client-typecheck
stage runs nightly/weekly/etc in master but not in merge requests on every commit