package:code_builder v4.12.0

• Add MixinBuilder.onTypes to support a mixin on clause with multiple
  superclass constraints (e.g. mixin Foo on A, B {}). Takes precedence over
  the existing single-type on field when non-empty.
• Ensure scoped lint ignores
  (such as // ignore_for_file: no_leading_underscores_for_library_prefixes)
  are emitted at the top of the file before library annotations and directives.
• Allow single quotes in strings passed to literalString(raw:true). This
  argument no longer guarantees a raw string is used, but results will have the
  same behavior.
• Correct type annotations on nullable and generic variables created with
  declareVar, declareFinal, and declareConst.
• Deprecate and remove uses of Expression.expression.
• Add control flow specs: Conditional, Branch, Condition,
  BooleanCondition, CaseCondition, ForLoop, ForInLoop, WhileLoop,
  Try, Catch, SwitchStatement, and CaseStatement.
• Add SwitchExpression and CaseExpression for switch expressions.
• Add Pattern AST and static methods for generating Dart 3 pattern matching
  syntax.
• Require Dart ^3.10.0