Use the GITHUB_TOKEN to avoid exceeding the API rate limit

As of a few days ago, plenty of workflow runs in git/git,
gitgitgadget/git and git-for-windows/git failed with message like this:

	Error: API rate limit exceeded for 172.176.196.48. (But here's
	the good news: Authenticated requests get a higher rate limit.
	Check out the documentation for more details.)

So let's try this.

Signed-off-by: Johannes Schindelin <[email protected]>

Author: dscho

action.yml

@@ -33,6 +33,13 @@ inputs:
     required: false
     description: 'Use @actions/cache to accelerate this Action'
     default: 'auto'
+  github-token:
+    description: >
+      Personal access token (PAT) used to call into GitHub's REST API.
+      We recommend using a service account with the least permissions necessary.
+      Also when generating a new PAT, select the least scopes necessary.
+      [Learn more about creating and using encrypted secrets](https://help.github.com/en/actions/automating-your-workflow-with-github-actions/creating-and-using-encrypted-secrets)
+    default: ${{ github.token }}
 runs:
   using: 'node16'
   main: 'dist/index.js'

main.ts

@@ -79,12 +79,14 @@ async function run(): Promise<void> {
 
     const architectureToDownload =
       architecture === 'aarch64' ? 'x86_64' : architecture
+    const githubToken = core.getInput('github-token')
     const verbose = core.getInput('verbose')
     const msysMode = core.getInput('msys') === 'true'
 
     const {artifactName, download, id} = await getViaGit(
       flavor,
-      architectureToDownload
+      architectureToDownload,
+      githubToken
     )
     const outputDirectory = core.getInput('path') || `C:/${artifactName}`
     let useCache: boolean

src/git.ts

@@ -74,7 +74,8 @@ async function clone(
 
 export async function getViaGit(
   flavor: string,
-  architecture: string
+  architecture: string,
+  githubToken?: string
 ): Promise<{
   artifactName: string
   id: string
@@ -90,7 +91,7 @@ export async function getViaGit(
     architecture
   )
 
-  const octokit = new Octokit()
+  const octokit = githubToken ? new Octokit({auth: githubToken}) : new Octokit()
   let head_sha: string
   if (flavor === 'minimal') {
     const info = await octokit.actions.listWorkflowRuns({