fix: drop require

src/util.ts

@@ -1,4 +1,5 @@
 import * as core from '@actions/core'
+import fs from 'fs'
 
 export type Input =
   | 'add'
@@ -49,6 +50,21 @@ export function parseBool(value: any) {
   } catch {}
 }
 
+export function readJSON(filePath: string) {
+  let fileContent: string
+  try {
+    fileContent = fs.readFileSync(filePath, { encoding: 'utf8' })
+  } catch {
+    throw `Couldn't read file. File path: ${filePath}`
+  }
+
+  try {
+    return JSON.parse(fileContent)
+  } catch {
+    throw `Couldn't parse file to JSON. File path: ${filePath}`
+  }
+}
+
 export function setOutput(name: Output, value: 'true' | 'false') {
   core.debug(`Setting output: ${name}=${value}`)
   outputs[name] = value