Jib authentification does not respect www-authenticate specification allowing Basic auth without specifying realm

[Mishkun]

Environment:

• Jib version: 3.3.2
• Build tool: Gradle
• OS: Macos Ventura 13.3.1

Description of the issue:
When trying to login to my self-hosted Docker registry, Jib fails with the following error:

Caused by: com.google.cloud.tools.jib.api.RegistryAuthenticationFailedException: Failed to authenticate with registry <my registry> because: 'Bearer' was not found in the 'WWW-Authenticate' header, tried to parse: Basic

Having a look to com.google.cloud.tools.jib.registry.RegistryAuthenticator#fromAuthenticationMethod I see that regexp used to determine authentification method has a space before the .*.

authenticationMethod.matches("^(?i)(basic) .*")

This makes jib to fail to select auth method given header WWW-Authenticate: Basic

Expected behavior:
According to https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/WWW-Authenticate#syntax it is allowed to use WWW-Authenticate: Basic without providing any realm/charset. Jib should allow that

Steps to reproduce:
Try to login to any registry responding with WWW-Authenticate: Basic header.

[chanseokoh]

#4035 should fix it.