backport allow-unsafe-pr-checkout to v2 (#2504)

* block checking out fork pr for pull_request_target and workflow_run (#2454)

* block checking out fork pr for some events

* address copilot and reviewer feedback

* run prettier formatting

* build

* update urls

* update readme

* update description and url again

* edit url one more time

* update error wording (#2467)

* bump upload-artifact

* rebuild

src/git-source-settings.ts

@@ -83,4 +83,10 @@ export interface IGitSourceSettings {
    * Indicates whether to add repositoryPath as safe.directory in git global config
    */
   setSafeDirectory: boolean
+
+  /**
+   * Opt-in to allow checking out fork pull request code from a workflow
+   * triggered by pull_request_target or workflow_run.
+   */
+  allowUnsafePrCheckout: boolean
 }