fix: add location directive for /explore

[kurokobo]

Summary

This is for plugins/beta branch

Add a location directive for /explore to prevent requests for /explore from being matched with /e and routed to the plugin daemon.

Closes #12570

Screenshots

Before	After

Checklist

Important

Please review the checklist below before submitting your pull request.

• This change requires a documentation update, included: Dify Document
• I understand that this PR may be closed in case there was no previous discussion or issues. (This doesn't apply to typos!)
• I've added a test for each change that was introduced, and I tried as much as possible to make a single atomic change.
• I've updated the documentation accordingly.
• I ran dev/reformat(backend) and cd web && npx lint-staged(frontend) to appease the lint gods

[Yeuoly]

LGTM

[Yeuoly]

Thanks for the patch!