⚡ Fix Head-of-Line Blocking in InMemory Job Backend

[Tuntii]

Optimized InMemoryBackend::pop to iterate through the queue and find the first ready job, instead of just checking the head. This prevents jobs scheduled in the future from blocking the execution of other ready jobs.

• Added reproduction test case crates/rustapi-jobs/tests/repro_blocking.rs.
• Modified crates/rustapi-jobs/src/backend/memory.rs to implement scanning pop.

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PR created automatically by Jules for task 17973034078689993578 started by @Tuntii

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[Copilot]

Pull request overview

This pull request fixes a head-of-line blocking issue in the InMemoryBackend where jobs scheduled for future execution would prevent currently-ready jobs from being processed. The fix modifies the pop() method to scan through the queue and find the first ready job, rather than just checking the head of the queue.

Changes:

• Added a comprehensive test case that reproduces the blocking scenario
• Modified InMemoryBackend::pop() to iterate through the queue and select the first job that is ready for execution

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
crates/rustapi-jobs/tests/repro_blocking.rs	Adds test demonstrating that a ready job (Job 2) can be processed even when a delayed job (Job 1) is at the head of the queue
crates/rustapi-jobs/src/backend/memory.rs	Changes pop() from checking only the front of the queue to scanning for the first ready job, fixing head-of-line blocking