Only write config file during postinstall if process env variables are present (#91793)

extensions/github-authentication/build/postinstall.js

@@ -20,7 +20,9 @@ function main() {
 		}
 	}
 
-	fs.writeFileSync(path.join(__dirname, '../src/common/config.json'), JSON.stringify(content));
+	if (Object.keys(content).length > 0) {
+		fs.writeFileSync(path.join(__dirname, '../src/common/config.json'), JSON.stringify(content));
+	}
 }
 
 main();