Spec changes to `using` in `switch`

[evanw]

JavaScript was apparently changed to disallow something that was previously allowed. Investigate this and potentially change esbuild to reject this syntax.

References:

• Disallow using/await using in a switch case/default clause rbuckton/ecma262#14
• Should reject using / await using in a switch case / default clause microsoft/TypeScript#62708
• fix: raises syntax errors on invalid using declarations acornjs/acorn#1374
• fix(parser): reject using / await using in a switch case / default clause oxc-project/oxc#15225