Revert "Merge branch '590532-block-nested-includes' into 'master'"

Purpose of revert

Revert "Merge branch '590532-block-nested-includes' into 'master'"

This reverts merge request !224850 (merged)

We shipped spec:include keyword to support reading inputs from a file, that trickled down an unintentional workaround to make it work in included configuration. Support in included configurations was never in plan, so we decided to block it via the reverting MR, but we had a couple of customers and internal team using the spec:include feature in included configurations. So we decided to revert the MR.

We already have the bug issue to track the bug behaviour of being used in included configurations.

Checklist

• Create an issue to reinstate the merge request and assign it to the author of the reverted merge request.
• If the revert is to resolve a broken 'master' incident, please read through the Responsibilities of the Broken master resolution DRI.
• If the revert involves a database migration, please read through Deleting existing migrations.
• Add the appropriate labels before the MR is created. We can skip CI/CD jobs only if the labels are added before the CI/CD pipeline is created.

Milestone info

• I am reverting something in the current milestone. No changelog is needed, and I've added a ~"regression:*" label.
• [] I am reverting something in a different milestone. A changelog is needed, and I've removed the ~"regression:*" label.

Related issues and merge requests