GitHub action 'execute-modified-python-file.yml' will only execute first file and ignore the rest when multiple files are modified at once

**About Bug or problem**
GitHub action to execute modified python file is implemented in `.github/workflows/execute-modified-python-file.yml`

This action executes any files that are modified in the repo. A JSON is generated listing the modified files and `run-modified-python.sh` will execute the file.
However, this only works properly when one file is modified at a time. If for example, two files are modifed at once, the JSON will list two files but only the first will be executed.
[This example GitHub action report](https://github.com/inspirezonetech/TeachMePythonLikeIm5/runs/3783386735?check_suite_focus=true) shows two files were modified but only the first file in the list was executed.

**Steps to reproduce**
Modify more than one file at once and commit them to repo.

**Potential fix**
Implement a loop that will scan through JSON list of modified files and execute each one by one.