CI: Add node16

[ryan-roemer]

Node16 with serverless at our current (old) version produces way, way too large of output files. See, e.g.

 34M	.test-zips/complex/yarn/baseline/individually.zip
 34M	.test-zips/complex/yarn/baseline/serverless-jetpack-complex.zip
1.8M	.test-zips/complex/yarn/jetpack/trace/individually.zip
1.8M	.test-zips/complex/yarn/jetpack/trace/serverless-jetpack-complex.zip
2.2M	.test-zips/complex/yarn/jetpack/deps/individually.zip
2.2M	.test-zips/complex/yarn/jetpack/deps/serverless-jetpack-complex.zip
 34M	.test-zips/complex/npm/baseline/individually.zip
 34M	.test-zips/complex/npm/baseline/serverless-jetpack-complex.zip
1.8M	.test-zips/complex/npm/jetpack/trace/individually.zip
1.8M	.test-zips/complex/npm/jetpack/trace/serverless-jetpack-complex.zip
2.2M	.test-zips/complex/npm/jetpack/deps/individually.zip
2.2M	.test-zips/complex/npm/jetpack/deps/serverless-jetpack-complex.zip
 42M	.test-zips/simple/yarn/baseline/serverless-jetpack-simple.zip
520K	.test-zips/simple/yarn/jetpack/trace/serverless-jetpack-simple.zip
872K	.test-zips/simple/yarn/jetpack/deps/serverless-jetpack-simple.zip
 43M	.test-zips/simple/npm/baseline/serverless-jetpack-simple.zip
568K	.test-zips/simple/npm/jetpack/trace/serverless-jetpack-simple.zip
856K	.test-zips/simple/npm/jetpack/deps/serverless-jetpack-simple.zip

Task

• See if an upgrade to serverless lib fixes this
• Enable node16 in github actions config.

[techytushar]

Hey I would like to work on this