Remove dead code: Composer cache file system

Proposal

Work was done to implement a solution for Composer v1 performance problems. This work was left incomplete and unused because supporting Composer v2 fixed the performance problems and we pushed #290288 (closed) to the backlog pending more demand.

In #331768 (closed) we identified that a recurring error was due to some of the code added in the first issue. An investigation was done, and it was verified that the code surrounding the composer cache files is not used and can be treated as dead code.

We should remove this code as it is stale and could create more errors/confusion in the future.

Notes

Here is some of the code that may need to be removed:

• a worker
• a lib object
• a rake task
• a model
• an uploader for the model above