GitHub action execute-modified-python-file.yml will not run when a new file is created and added to repo

**About Bug or problem**
The GitHub action to execute python file will not run when a file is created rather than modified.
This is because the action is designed only to check files that were **modified** and so will ignore files that are new to the repo.

**Steps to reproduce**
Create a brand new python file and add to the repo. The GitHub action will not see any files as being modified and will print:
```
Run echo "job: running script to execute modified file:"
job: running script to execute modified file:
run-sh: Inside run-modified-python.sh
run-sh: Content of files_modified.json: []
run-sh: After parsing, file to execute:
run-sh: File modified is not a python file! Will not execute
job: Done
```

**Potential fix**
Modify action `execute-modified-python-file.yml` to detect when new files are added to the repo and execute them.

Inizia leggendo execute-modified-python-file.yml e run-modified-python.sh, quindi riproduci il problema aggiungendo un file Python completamente nuovo e controllando files_modified.json e l'output dell'action. L'attività è completata quando l'action rileva i file Python appena aggiunti e li esegue invece di segnalare che non ci sono file modificati.

Scritto dal modello di indicizzazione a partire dal testo della issue.