CCAP-304: Add support for background jobs

[jamesiarmes]

🔗 Jira ticket

CCAP-304

✍️ Description

Implements delayed_job with a single recurring job that deactivates expired authentication keys.

📷 Design reference

Tech spec

🧪 Testing instructions

• Build the docker image by running docker compose build
• Launch (or update) the service by running docker compose up -d
• Run docker compose logs worker to verify that the worker is running
• Run docker compose exec worker bundle exec rake jobs:queue and verify it returns stats from the worker

✅ Completion tasks

• Added relevant tests
• Meets acceptance criteria

[github-actions]

🔍 Vulnerabilities of pr-9:latest

📦 Image Reference pr-9:latest

digest	sha256:df9160edc78bfa2e39f3a1cbb9ada2b8c99c15f022c3268144997034028bd047
vulnerabilities
size	516 MB
packages	736

📦 Base Image ruby:3

also known as	3-bookworm 3.3 3.3-bookworm 3.3.4 3.3.4-bookworm bookworm latest
digest	sha256:6b49252a37a7664623dee0a132ea0b3a936c100ed6d9520318f4823302c396af
vulnerabilities

[cram-cfa]

from what i understand of this, it looks good to me!