Drop support for Node 16

[aleclarson]

Things to update

• The tsconfig.json files:
  

  radashi/tsconfig.json

  Lines 12 to 13 in 028de5e

  	"target": "es2017",
  	"lib": ["es2017"],

• The update-browserslist script:
  

  radashi/scripts/update-browserslist/src/main.ts

  Line 21 in 028de5e

  targets.push('node >= 16')

• Other things...?