Make `minimumReleaseAgeTimestamp=required` in next breaking change

[jamietanna]

In #38363 / #38478, we're introducing minimumReleaseAgeTimestamp=optional (by default, and minimumReleaseAgeTimestamp=required in config:best-practices`)

This is something we should enforce by default, but as this is a change in behaviour - even if it does introduce improved security and prectability - we should wait until the next breaking change

This will be added in the next breaking change, after #38478 is complete

[RahulGautamSingh]

Shouldn't we first fix the unexpected behavior in minimumReleaseAge first?

[jamietanna]

Shouldn't we first fix the unexpected behavior in minimumReleaseAge first?

Which unexpected behaviour are you talking about? (There may be a couple of things you're referring to, so want to be sure!)

[RahulGautamSingh]

Problem: PRs getting created from existing/old branches

[jamietanna]

Do we have a Discussion/Issue tracking that issue?

But yes, either way - we'll be sorting that before #37952 is completed, which will be done before this issue here