Add support for setting ssh encryption key in Zero Trust

[jroyal]

Description

We currently allow users to set a public key that can used to encrypt their SSH logs in the UI. We are adding support for that key in cloudflare-go and terraform.

Has your change been tested?

Unit tests

Screenshots (if appropriate):

This is the setting we are adding support for.

Types of changes

What sort of change does your code introduce/modify?

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.
• All new and existing tests passed.
• This change is using publicly documented in cloudflare/api-schemas
  and relies on stable APIs.

[github-actions]

changelog detected ✅

[jroyal]

API docs change is in staging. Once that has been released this should be good to go.

[github-actions]

This functionality has been released in v0.79.0.

For further feature requests or bug reports with this functionality, please create a new GitHub issue following the template. Thank you!