[Python Gitignore] Ignore Sage's parsed files

Ignore Sage's parsed files (*.sage.py) that are left after running a .Sage program.

Python.gitignore

@@ -76,6 +76,9 @@ target/
 # celery beat schedule file
 celerybeat-schedule
 
+#Sage parsed files
+*.sage.py
+
 # dotenv
 .env