Adding Github or Bitbucket host keys in SSH Keys section results in immediate removal without warning

Issue Summary

When users attempt to add github.com or bitbucket.org host keys to the SSH Keys section under Repository Settings, these entries are immediately removed without any notice or warning. To improve user experience and clarity, it would be beneficial instead of just removing the values, the system provided a warning mentioning that these keys are already added and do not need to be manually inserted.

Steps to Reproduce

1. Navigate to Repository Settings.
2. Go to the SSH Keys section under the Pipelines.
3. Attempt to add the address for the known host (either github.com or bitbucket.org).
4. Click the Fetch button to retrieve the host's fingerprint.

Expected Results

As these keys are automatically added provide a warning or notice explaining that these keys are automatically added to all pipelines and thus do not need to be manually entered.

Actual Results

The user's attempt to add a known host key for github.com or bitbucket.org results in the immediate removal of the entry without any explanation or warning