Loading the contents of test_files_list.txt into a DataFrame

Reading the `repourl` and test files for each repo from `test_files_list.txt` and load them into a DataFrame and then merge this to the existing df `updated_local_github_df_test_count.csv`

Start by locating `test_files_list.txt` and the code that produces or loads `updated_local_github_df_test_count.csv`. Trace how repository URLs and test-file entries are represented, then define completion as loading those contents into a DataFrame and merging the result with the existing DataFrame without losing the repository associations.

Written by the indexing model from the issue text.