chore: Add analyzer languages.

[yumatan]

$ flutter create → Generate analysis_options.yaml automatically.

Set the analyzer language rules.

• https://github.com/dart-lang/language/blob/main/resources/type-system/strict-casts.md
• https://github.com/dart-lang/language/blob/main/resources/type-system/strict-inference.md
• https://github.com/dart-lang/language/blob/main/resources/type-system/strict-raw-types.md