Remove temporary x-pack/legacy/plugins/watcher eslint overrides

[spalger]

In order to move forward with #49244 we needed to disable some rules in x-pack/legacy/plugins/watcher. We need to remove the related overrides and get the package passing these rules pretty soon.

// .eslintrc.js
{
  files: ['x-pack/legacy/plugins/watcher/**/*.{js,ts,tsx}'],
  rules: {
    'react-hooks/rules-of-hooks': 'off',
    'react-hooks/exhaustive-deps': 'off',
  },
},

[elasticmachine]

Pinging @elastic/es-ui (Team:Elasticsearch UI)

[jloleysens]

Addressed in #50908