ci: Add nextjs client to size limit check (#4203)

Author: AbhiPrasad

.size-limit.js

@@ -17,6 +17,12 @@ module.exports = [
     import: '{ init }',
     limit: '100 KB',
   },
+  {
+    name: '@sentry/nextjs Client - Webpack',
+    path: 'packages/nextjs/esm/index.client.js',
+    import: '{ init }',
+    limit: '100 KB',
+  },
   {
     name: '@sentry/browser + @sentry/tracing - CDN Bundle (gzipped)',
     path: 'packages/tracing/build/bundle.tracing.min.js',