[Misc] fix: add miss Close() for redis client

[googs1025]

Pull Request Description

[Please provide a clear and concise description of your changes here]

Related Issues

Resolves: None

Important: Before submitting, please complete the description above and review the checklist below.

---

Contribution Guidelines (Expand for Details)

We appreciate your contribution to aibrix! To ensure a smooth review process and maintain high code quality, please adhere to the following guidelines:

Pull Request Title Format

Your PR title should start with one of these prefixes to indicate the nature of the change:

• [Bug]: Corrections to existing functionality
• [CI]: Changes to build process or CI pipeline
• [Docs]: Updates or additions to documentation
• [API]: Modifications to aibrix's API or interface
• [CLI]: Changes or additions to the Command Line Interface
• [Misc]: For changes not covered above (use sparingly)

Note: For changes spanning multiple categories, use multiple prefixes in order of importance.

Submission Checklist

• PR title includes appropriate prefix(es)
• Changes are clearly explained in the PR description
• New and existing tests pass successfully
• Code adheres to project style and best practices
• Documentation updated to reflect changes (if applicable)
• Thorough testing completed, no regressions introduced

By submitting this PR, you confirm that you've read these guidelines and your changes align with the project's contribution standards.

[Copilot]

Pull Request Overview

This PR addresses the missing Close() call for the Redis client to ensure proper resource cleanup in both test and production code.

• Added defer statements to close the Redis client in the test file and production main files.
• Introduced a deferred function with error logging in the production code to capture any issues during client closure.

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
test/e2e/vtc_routing_test.go	Added defer redisClient.Close() to ensure cleanup in tests.
cmd/plugins/main.go	Added a deferred function with error checking for Close().
cmd/metadata/main.go	Added a deferred function with error checking for Close().