refactor: remove `Ctx` generic from payments core

[Chethan-rao]

Type of Change

• [ ] Bugfix
• [ ] New feature
• [ ] Enhancement
• [x] Refactoring
• [ ] Dependency updates
• [ ] Documentation
• [ ] CI/CD

Description

This PR removes the Ctx generic being used in payments core as this is not required anymore. This PR also fixes the failing typos CI check

Additional Changes

• [ ] This PR modifies the API contract
• [ ] This PR modifies the database schema
• [ ] This PR modifies application configuration/environment variables

Motivation and Context

How did you test it?

Checklist

• [x] I formatted the code cargo +nightly fmt --all
• [x] I addressed lints thrown by cargo clippy
• [x] I reviewed the submitted code
• [ ] I added unit tests for my changes where possible