feat: add retry (#79)

resolves #71

- Add p-retry library
- Extract logic to new functions to improve the usage of retry logic

tests/main-token-get-owner-set-repo-fail-response.test.js

@@ -0,0 +1,39 @@
+import { test } from "./main.js";
+
+// Verify `main` retry when  the GitHub API returns a 500 error.
+await test((mockPool) => {
+  process.env.INPUT_OWNER = 'actions'
+  process.env.INPUT_REPOSITORIES = 'failed-repo';
+  const owner = process.env.INPUT_OWNER
+  const repo = process.env.INPUT_REPOSITORIES
+  const mockInstallationId = "123456";
+
+  mockPool
+    .intercept({
+      path: `/repos/${owner}/${repo}/installation`,
+      method: "GET",
+      headers: {
+        accept: "application/vnd.github.v3+json",
+        "user-agent": "actions/create-github-app-token",
+        // Intentionally omitting the `authorization` header, since JWT creation is not idempotent.
+      },
+    })
+    .reply(500, 'GitHub API not available')
+    
+    mockPool
+    .intercept({
+      path: `/repos/${owner}/${repo}/installation`,
+      method: "GET",
+      headers: {
+        accept: "application/vnd.github.v3+json",
+        "user-agent": "actions/create-github-app-token",
+        // Intentionally omitting the `authorization` header, since JWT creation is not idempotent.
+      },
+    })
+    .reply(
+      200,
+      { id: mockInstallationId },
+      { headers: { "content-type": "application/json" } }
+    );
+
+});