feat: remove v1/otomi/values endpoint and update maintenance page

[ferruhcihan]

📌 Summary

This PR removes v1/otomi/values endpoint and updates maintenance page.

PRs: apl-core | apl-api

🔍 Reviewer Notes

Considerations

• I have tested the changes in both light and dark mode.
• I have considered the need for new unit tests.
• I have tested the changes on a cluster.
• I have included relevant documentation updates.
• I have an approved Figma design or have reflected my changes in Figma
• I have verified that the UI/UX is consistent in major browsers (e.g., Chrome, Firefox, Safari, Edge).
• I have tested the changes for responsiveness in different screen resolutions.
• I have tested expected error states and verified that the user is presented with informative error messages.
• I have tested the feature with unusual or extreme inputs (e.g., very long strings, empty states, clicking a button multiple times quickly).