Bump babel to 7.14.x for typescript 4.3 support (#36465)

* chore(babel): bump packages to 7.14.x

* chore(babel): remove plugin-proposal-class-properties and plugin-proposal-private-methods

these plugins are now enabled by default in preset-env

package.json

@@ -66,18 +66,16 @@
     ]
   },
   "devDependencies": {
-    "@babel/core": "7.13.14",
-    "@babel/plugin-proposal-class-properties": "7.13.0",
-    "@babel/plugin-proposal-nullish-coalescing-operator": "7.13.8",
-    "@babel/plugin-proposal-object-rest-spread": "7.13.8",
-    "@babel/plugin-proposal-optional-chaining": "7.13.12",
-    "@babel/plugin-proposal-private-methods": "7.13.0",
+    "@babel/core": "7.14.6",
+    "@babel/plugin-proposal-nullish-coalescing-operator": "7.14.5",
+    "@babel/plugin-proposal-object-rest-spread": "7.14.7",
+    "@babel/plugin-proposal-optional-chaining": "7.14.5",
     "@babel/plugin-syntax-dynamic-import": "7.8.3",
-    "@babel/plugin-transform-react-constant-elements": "7.13.13",
-    "@babel/plugin-transform-runtime": "^7.13.10",
-    "@babel/preset-env": "7.13.12",
-    "@babel/preset-react": "7.13.13",
-    "@babel/preset-typescript": "7.13.0",
+    "@babel/plugin-transform-react-constant-elements": "7.14.5",
+    "@babel/plugin-transform-runtime": "^7.14.5",
+    "@babel/preset-env": "7.14.7",
+    "@babel/preset-react": "7.14.5",
+    "@babel/preset-typescript": "7.14.5",
     "@emotion/eslint-plugin": "11.2.0",
     "@grafana/api-documenter": "7.11.2",
     "@grafana/api-extractor": "7.10.1",

scripts/webpack/babel.config.js

@@ -2,7 +2,6 @@ module.exports = function getBabelConfig(options = {}) {
   return {
     cacheDirectory: true,
     babelrc: false,
-    // Note: order is top-to-bottom and/or left-to-right
     // Note: order is bottom-to-top and/or right-to-left
     presets: [
       [
@@ -36,8 +35,6 @@ module.exports = function getBabelConfig(options = {}) {
           allowDeclareFields: true,
         },
       ],
-      ['@babel/plugin-proposal-class-properties', { loose: true }],
-      ['@babel/plugin-proposal-private-methods', { loose: true }],
       ['@babel/plugin-proposal-object-rest-spread', { loose: true }],
       '@babel/plugin-transform-react-constant-elements',
       '@babel/plugin-proposal-nullish-coalescing-operator',