Export BAZELISK_GITHUB_TOKEN variable

Fixes #57

config.js

@@ -123,6 +123,9 @@ if (externalCacheConfig) {
   }
 }
 
+const token = core.getInput('token')
+core.exportVariable('BAZELISK_GITHUB_TOKEN', token)
+
 module.exports = {
   baseCacheKey,
   bazeliskCache: {

index.js

@@ -69,8 +69,7 @@ async function downloadBazelisk() {
     filename = `${filename}.exe`
   }
 
-  const token = core.getInput('token')
+  const octokit = github.getOctokit(process.env.BAZELISK_GITHUB_TOKEN, {
-  const octokit = github.getOctokit(token, {
     baseUrl: 'https://api.github.com'
   })
   const { data: releases } = await octokit.rest.repos.listReleases({