cask/dsl: typed: strict

[botantony]

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Part of #17297

[Copilot]

Pull request overview

This PR upgrades three cask DSL files from typed: true to typed: strict Sorbet type checking, adding comprehensive type annotations to satisfy stricter type requirements.

• Adds explicit type signatures for methods and instance variables across version, depends_on, and container DSL classes
• Converts implicit type inference to explicit T.let declarations for constants and instance variables
• Fixes a potential bug in invalid_characters method by adding explicit .to_s conversion

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

File	Description
Library/Homebrew/cask/dsl/version.rb	Upgraded to strict typing with method signatures, T.let for DIVIDERS constant, and explicit type conversions
Library/Homebrew/cask/dsl/depends_on.rb	Upgraded to strict typing with detailed method signatures, converted attr_readers to methods with lazy initialization, and T.let annotations
Library/Homebrew/cask/dsl/container.rb	Upgraded to strict typing with method signatures and T.let annotations for instance variables

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[MikeMcQuaid]

Looks good thanks @botantony!