Bump mediocregopher/radix to v4

[nghiant3223]

Problem

The ratelimit package currently depends on mediocregopher/radix v3, which does not support context-aware operations.

As a result, when a context is canceled (e.g., due to client timeouts), ratelimit may still:

1. Wait for a connection from the Redis connection pool
2. Execute Redis commands after the request has been canceled

This leads to unnecessary resource usage and potential latency under load.

Proposal

Upgrade to mediocregopher/radix v4, which introduces support for context.Context in command execution.

Benefits

• Proper context cancellation handling
• Reduced resource usage when requests are aborted
• Better integration with modern Go context patterns

[nghiant3223]

Hi @collin-lee. Please take a look. Thank you!

[github-actions[bot]]

This issue has been automatically marked as stale because it has not had activity in the last 30 days. It will be closed in the next 7 days unless it is tagged "help wanted" or "no stalebot" or other activity occurs. Thank you for your contributions.

[github-actions[bot]]

This issue has been automatically closed because it has not had activity in the last 37 days. If this issue is still valid, please ping a maintainer and ask them to label it as "help wanted" or "no stalebot". Thank you for your contributions.