Limit patch updates frequency to every 2 weeks for some packages

What does this MR do and why?

Some units get very frequents updates (as they use semantic release), to limit a bit the amount of MR created by Renovate this propose to add a new rules:

For thanos and postgresql (we could add other unit if needed), we limit the patch updates (Minor and major will not be affected) creation to the 1st and 14th of each month (Scheduling can be adapted too).

Related reference(s)

close #1522 (closed)