Remove Babel loose: true class except for JS Interpreter and Maker

[mikeharv]

Alternative to:

• Remove Babel loose: true class transform to fix recursion in transpiled accessors #65894

This PR removes "loose": true from the @babel/plugin-transform-classes plugin only when transpiling Blockly.

In our environment, "loose": true causes Babel to transpile super.prop = value as this.prop = value. When Blockly introduced the size_ accessor in FieldInput, our transpilation led to infinite recursion: super.size_ = val was rewritten as this.size_ = val.

This override impacts everywhere except two specific folders, hopefully avoiding the regressions introduced by #65894

This change avoids the recursion bug introduced by Babel rewriting super.size_ = val as this.size_ = val, which broke Blockly’s new accessor-based Field implementation.

PR Checklist:

• Tests provide adequate coverage
• Privacy and Security impacts have been assessed
• Code is well-commented
• New features are translatable or updates will not break translations
• Relevant documentation has been added or updated
• User impact is well-understood and desirable
• Pull Request is labeled appropriately
• Follow-up work items (including potential tech debt) are tracked and linked