docs(errors): minor update to failed-to-find-server-action error page (#76296)

## Why?

Follow up to #75678 (comment).

Author: samcx

errors/failed-to-find-server-action.mdx

@@ -12,7 +12,7 @@ When self-hosting your Next.js application across multiple servers, each server
 
 To mitigate this, you can overwrite the encryption key using the `process.env.NEXT_SERVER_ACTIONS_ENCRYPTION_KEY` environment variable. Specifying this variable ensures that your encryption keys are persistent across builds, and all server instances use the same key. This variable **must** be AES-GCM encrypted.
 
-In a non-self-hosted environment, you can use a feature such as [Skew Protection](https://vercel.com/docs/deployments/skew-protection) to ensure assets and functions from the previous version are still available, even after a new version is deployed.
+If you are deploying your Next.js application to Vercel, you can use the feature [Skew Protection](https://vercel.com/docs/deployments/skew-protection) to ensure assets and functions from the previous version are still available, even after a new version is deployed.
 
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