Please add support for Conditional Stages and Jobs.

I'll provide an example for why this is useful for Jobs; I think the argument for Stages is similar, though that's open for debate.

Example for Jobs

There are many use-cases for doing some kind of logic in one stage, and then conditionally executing a subset of parallel jobs in the next stage based on that logic.

For example: say you have 20 jobs within a stage of a plan, each of which takes 15 minutes. You may want some logic that decides a subset of those 20 jobs to build on a commit.

Why Conditional Tasks is not the same

Currently, it's possible to just add a condition to every task within each of those jobs as a workaround, but that still schedules every job to a build agent, which would cause significant churn, and may have nontrivial overhead depending on cache settings.

A better solution would be to allow Bamboo to selectively run a subset of the jobs conditionally.

Previous ticket and why this is still relevant

A previous ticket for this ask (https://jira.atlassian.com/browse/BAM-15547) was erroneously closed in 2015 as being solved by "Conditional Tasks." These are not the same feature, as evidenced by the multiple comments within the last 3 years on the older ticket.