[compiler] Remove @babel/plugin-proposal-private-methods (#34715)

redo of #34458 but fixing up prettier

Co-authored-by: Arnaud Barré <arnaud.barre@carbometrix.com>

scripts/rollup/bundles.js

@@ -1253,7 +1253,6 @@ const bundles = [
     preferBuiltins: true,
     externals: [
       '@babel/core',
-      '@babel/plugin-proposal-private-methods',
       'hermes-parser',
       'zod',
       'zod-validation-error',