refactor: Fix phpstan varTag.type errors

[neznaika0]

Description

• Redis::scan() does not return Redis.
• config() already supports the hint for classes. Removed the creation of a one-time variable.
• TimeTrait::$timezone it can be a string during initialization.
• It seems that Closure(mixed...) cannot be specified, so I only changed the return type.

Checklist:

• Securely signed commits
• Component(s) with PHPDoc blocks, only if necessary or adds value
• Unit testing, with >80% coverage
• User guide updated
• Conforms to style guide