[policy, no patch] Clarify the policy around backporting changes with potential issues

Adding to my policy review list.

I think @xjm's sentence here still describes the status quo several years later

OTOH we also adopted the policy that we default to committing borderline things to the dev minor only and only backport things that are easy/safe or high priority.

I still see quite a few cases where people ask why x somewhat tricky bugfix hasn't been backported, was going to say we should add a note about it to https://www.drupal.org/about/core/policies/core-change-policies/allowed-... → , but it's already on there. We should probably update that issue for the 'main' branch though now we're always targeting issues at that branch and moving the issue to an older branch only if we commit the backport there.

I agree the docs need updating and have made a note on 🌱 [Policy] Branch Naming: Use an 11.x branch for HEAD, then use 'main' when d.o can support it Fixed as well as adding to my to do list.

Since current practice is documented and the policies have been updated since 2016 I am closing this as outdated.

Changing to latest version when this was closed.

Crediting discussion participants.