[core] Remove outdated babel proposal plugins (mui#36795)

Co-authored-by: ZeeshanTamboli <zeeshan.tamboli@gmail.com>

Author: 2 people

babel.config.js

@@ -62,12 +62,6 @@ module.exports = function getBabelConfig(api) {
       },
     ],
     'babel-plugin-optimize-clsx',
-    // Need the following 3 proposals for all targets in .browserslistrc.
-    // With our usage the transpiled loose mode is equivalent to spec mode.
-    ['@babel/plugin-proposal-class-properties', { loose: true }],
-    ['@babel/plugin-proposal-private-methods', { loose: true }],
-    ['@babel/plugin-proposal-private-property-in-object', { loose: true }],
-    ['@babel/plugin-proposal-object-rest-spread', { loose: true }],
     [
       '@babel/plugin-transform-runtime',
       {

package.json

@@ -76,8 +76,6 @@
     "@babel/cli": "^7.21.0",
     "@babel/core": "^7.21.4",
     "@babel/node": "^7.20.7",
-    "@babel/plugin-proposal-class-properties": "^7.18.6",
-    "@babel/plugin-proposal-object-rest-spread": "^7.20.7",
     "@babel/plugin-transform-object-assign": "^7.18.6",
     "@babel/plugin-transform-react-constant-elements": "^7.21.3",
     "@babel/plugin-transform-runtime": "^7.21.4",
@@ -210,11 +208,6 @@
   "resolutions": {
     "**/@babel/core": "^7.21.4",
     "**/@babel/code-frame": "^7.21.4",
-    "**/@babel/plugin-proposal-class-properties": "^7.18.6",
-    "**/@babel/plugin-proposal-object-rest-spread": "^7.20.7",
-    "**/@babel/plugin-proposal-nullish-coalescing-operator": "^7.18.6",
-    "**/@babel/plugin-proposal-numeric-separator": "^7.18.6",
-    "**/@babel/plugin-proposal-optional-chaining": "^7.21.0",
     "**/@babel/plugin-transform-destructuring": "npm:@minh.nguyen/plugin-transform-destructuring@^7.5.2",
     "**/@babel/plugin-transform-runtime": "^7.21.4",
     "**/@babel/preset-env": "^7.21.4",