fix: add explicit undefined for optional types (#136)

* chore(deps): update dependency @octokit/tsconfig to v4

* fix add explicit undefined

---------

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Co-authored-by: wolfy1339 <[email protected]>

Author: renovate[bot]

package-lock.json

@@ -22,7 +22,7 @@
   "author": "Gregor Martynus (https://twitter.com/gr2m)",
   "license": "ISC",
   "devDependencies": {
-    "@octokit/tsconfig": "^3.0.0",
+    "@octokit/tsconfig": "^4.0.0",
     "@types/node": "^22.15.29",
     "@vitest/coverage-v8": "^3.0.0",
     "esbuild": "^0.25.0",

package.json

@@ -3,13 +3,13 @@ import { existsSync, readdirSync, readFileSync } from "node:fs";
 import { VERSION } from "./version.js";
 
 type Options = {
-  filepath?: string;
+  filepath?: string | undefined;
   env?: {
-    PRIVATE_KEY?: string;
-    PRIVATE_KEY_PATH?: string;
+    PRIVATE_KEY?: string | undefined;
+    PRIVATE_KEY_PATH?: string | undefined;
     [key: string]: string | undefined;
   };
-  cwd?: string;
+  cwd?: string | undefined;
 };
 
 const pkcs1Begin = "-----BEGIN RSA PRIVATE KEY-----";