remove invalid links for flutter and python books (#10366)

books/free-programming-books-id.md

@@ -61,12 +61,6 @@
 * [Tutorial CodeIgniter 4](http://mfikri.com/artikel/tutorial-codeigniter4)
 
 
-### Flutter
-
-* [Belajar Flutter](https://belajarflutter.com) - Herry Prasetyo (HTML)
-* [Flutter dan Flutlab](https://utter.academy/uploads/lesson_files/2f0c5c74e9488d4c9c734e4264e5869e.pdf) - Utter academy (PDF)
-
-
 ### Git
 
 * [Belajar Git untuk Pemula](https://github.com/petanikode/belajar-git) - Ahmad Muhardian, Petani Kode (HTML)
@@ -204,7 +198,6 @@
 
 * [Belajar Python](http://www.belajarpython.com)
 * [Cepat Mahir Python](https://gilacoding.com/upload/file/Python.pdf) - Hendri, `edt.:` Romi Satria Wahono (PDF)
-* [Dasar Pemrograman Python](https://www.pythonindo.com/tutorial-python-dasar/)
 * [Dasar Pengenalan Pemrograman Python](https://play.google.com/store/books/details/Rolly_Maulana_Awangga_Dasar_dasar_Python?id=YpzDDwAAQBAJ) - Rolly Maulana AwanggaRayhan *(Membutuhkan akun Google Play Books atau email yang valid)*
 * [Kursus Singkat Machine Learning dengan TensorFlow API](https://developers.google.com/machine-learning/crash-course?hl=id)
 * [Python Untuk Pemula](https://santrikoding.com/ebook/python-untuk-pemula) - Rizqi Maulana