fix type errors

Author: owickstrom

.claude/settings.local.json

@@ -0,0 +1,7 @@
+{
+  "permissions": {
+    "allow": [
+      "Bash(npm run *)"
+    ]
+  }
+}

src/main.ts

@@ -152,7 +152,10 @@ async function run(): Promise<void> {
     positionals.push(...splitCommand(command));
   }
 
-  const env: NodeJS.ProcessEnv = { ...process.env };
+  const env: Record<string, string> = {};
+  for (const [key, value] of Object.entries(process.env)) {
+    if (value !== undefined) env[key] = value;
+  }
   if (driver === 'browser' && !env.CHROME) {
     const chromeVersion = core.getInput('chrome-version') || 'stable';
     const useCache = parseBool(core.getInput('cache'), 'cache');