[testing-karma] update karma-esm to the latest version

[phetw]

@open-wc/testing-karma should update @open-wc/karma-esm to version with the latest version of es-dev-server which uses newer version of @rollup/plugin-node-resolve. Otherwise there will be 2 versions of this rollup plugins and different configs need to be maintain when using @open-wc/testing-karma with es-dev-server

├─┬ @open-wc/testing-karma@3.4.8
│ └─┬ @open-wc/karma-esm@2.16.18
│   └─┬ es-dev-server@1.60.2
│     └── @rollup/plugin-node-resolve@7.1.3 
└─┬ es-dev-server@2.1.0
  └── @rollup/plugin-node-resolve@11.1.1