chore(job_attachments): remove hard-coded endpoint

[gahyusuh]

What was the problem/requirement? (What/Why)

The Job Attachments module contains a hard-coded service endpoint constant that is currently not being used anywhere in the codebase. Also, defining such endpoint within the module (or library) seems incorrect.

What was the solution? (How)

Removed the hard-coded service endpoint from the Job Attachments module

What is the impact of this change?

It's a minor clean-up. This removal has no impact on the existing functionality as the constant was not in use.

How was this change tested?

• Ran hatch run lint && hatch run test and made sure that all unit tests passed.
• Performed an end-to-end test in the Beta environment by submitting a job through CLI --> processing it with a worker agent (CMF) to ensure there are no issues during the process.

Was this change documented?

No.

Is this a breaking change?

No.