Add legacy note on prometheus tile (#10561)
Add legacy note on prometheus tile (#10561)

* Add legacy note

* Update prometheus/manifest.json
DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core,DataDog/integrations-core