Encryption method validation error incorrectly highlights the Encryption Key field instead of Encryption Method

Problem/Motivation

When adding a new Encryption Profile at admin/config/system/encryption/profiles/add without any encryption method modules installed, submitting the form correctly shows the error message:

No encryption method selected.

However, the red validation-error highlight is applied to the Encryption Key field, not the Encryption Method field — even though Encryption Method is the empty/invalid field and Encryption Key is correctly filled in. This is misleading and makes it look like the Key field is the problem, when it isn't.

Steps to reproduce

1. Install and enable Encrypt modules
2. Create a valid Key entity
3. Go to admin/config/system/encryption/profiles/add.
4. Fill in Label and select the previously created Key under Encryption Key.
5. Leave Encryption Method empty
6. Click Save.