Backport COMPOSER_END_CODE check to D7 template

Problem/Motivation

For the D10+ template we check the success of each Composer job, and/or try to detect when something has gone wrong which has not caused the job to end in a failure code. Then we use this at the start of the other jobs to alert of the real problem.

It would be good to backport this to the D7 tempate - see comment #8 in #3518579-8: Improvements in log output, consistency in syntax, alignment with D7 → and the errors in this D7 composer job which did not fail the job.

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes