chore(deps): upgrade to node v20 (#536)

- node v14 is EoL and has been [since April 2023](https://github.com/nodejs/Release/blob/68840fae8fdaa59bf9431661238dbb86b4390829/README.md?plain=1#L7)
- node v20 is the [current LTS version](https://github.com/nodejs/Release/blob/9cf9c6ed8178e88c74dfa1921a793701e1d162c4/README.md?plain=1#L8)

- due to an old version of Storybook / Webpack, we have to run all Storybook scripts with `NODE_OPTIONS='--openssl-legacy-provider'`
  - this must be used if we use newer versions of node without upgrading Storybook + Webpack
    - unfortunately, upgrading Storybook is significantly easier said than done, especially since there are 3 different Storybook builds in this repo (v1, v2, and `antd`)
      - so put that off for now (or ever? since this repo is not maintained much anymore)
  - note that this is an insecure run-time configuration (which is why it was deprecated and is legacy), but since it is only used in development, it's not a significant vulnerability

Signed-off-by: Anton Gilgur <agilgur5@gmail.com>

.nvmrc

@@ -1 +1 @@
-v14
+v20

package.json

@@ -10,14 +10,14 @@
         "antd"
     ],
     "scripts": {
-        "build": "build-storybook -o ./dist/storybook",
+        "build": "NODE_OPTIONS='--openssl-legacy-provider' build-storybook -o ./dist/storybook",
         "lint": "eslint --ext .tsx .",
         "test": "jest",
         "utils:icons": "rm -f src/assets/fonts/* && node ./scripts/icons/generator.js",
-        "start": "start-storybook -p 6006",
-        "start-v2": "start-storybook -c ./v2/.storybook -s ./v2/.storybook/images -p 6006",
-        "build-v2": "build-storybook -o ./dist/storybook-v2 -c ./v2/.storybook",
-        "start-antd": "start-storybook -c antd/.storybook -s antd/.storybook/images -p 6006",
+        "start": "NODE_OPTIONS='--openssl-legacy-provider' start-storybook -p 6006",
+        "start-v2": "NODE_OPTIONS='--openssl-legacy-provider' start-storybook -c ./v2/.storybook -s ./v2/.storybook/images -p 6006",
+        "build-v2": "NODE_OPTIONS='--openssl-legacy-provider' build-storybook -o ./dist/storybook-v2 -c ./v2/.storybook",
+        "start-antd": "NODE_OPTIONS='--openssl-legacy-provider' start-storybook -c antd/.storybook -s antd/.storybook/images -p 6006",
         "compile-less-antd": "gulp compileLess"
     },
     "dependencies": {