Make node-fetch available

src/async-function.ts

@@ -4,6 +4,7 @@ import {Context} from '@actions/github/lib/context'
 import {GitHub} from '@actions/github/lib/utils'
 import * as glob from '@actions/glob'
 import * as io from '@actions/io'
+import fetch from 'node-fetch'
 
 const AsyncFunction = Object.getPrototypeOf(async () => null).constructor
 
@@ -14,6 +15,7 @@ type AsyncFunctionArguments = {
   exec: typeof exec
   glob: typeof glob
   io: typeof io
+  fetch: typeof fetch
   require: NodeRequire
   __original_require__: NodeRequire
 }