Need to handle exceptions specific to exception types

[reniacorreya]

Exceptions should be handled specific to the exception types in the following modules:

1. https://github.com/kiranbaby14/Analysis-of-GAP-programming-practices-on-GitHub/blob/main/scripts/get_github_files.py

2. https://github.com/kiranbaby14/Analysis-of-GAP-programming-practices-on-GitHub/blob/main/scripts/get_real_pgm_files_manually.py

3. https://github.com/kiranbaby14/Analysis-of-GAP-programming-practices-on-GitHub/blob/main/utils/files.py