fixup! feat: migrate HelmRepository to runtime/secrets v0.66.0 with strict BasicAuth validation

Signed-off-by: cappyzawa <[email protected]>

Author: cappyzawa

docs/spec/v1/helmrepositories.md

@@ -370,7 +370,8 @@ credentials for the repository.
 
 To authenticate towards a Helm repository using basic access authentication
 (in other words: using a username and password), the referenced Secret is
-expected to contain `.data.username` and `.data.password` values.
+expected to contain both `.data.username` and `.data.password` values.
+**Note:** Providing only one of these values (username or password) will result in an authentication error.
 
 For example: