Update to Django 5.0

[jdanielnd]

Changes Made:

• Updated all development dependencies to address security vulnerabilities.
• Ensured compatibility with Django 3.2+ by addressing changes in the internal handling of Decimal fields.
• Introduced support for Django's JSONField to enhance data storage capabilities.
• Created Github Action workflow for running tests (you can see the actions running here)

Compatibility

• Verified compatibility with Python versions 3.10, 3.11, and 3.12.
• Confirmed compatibility with Django versions >3.2 to the latest (5.0.2).

These updates enhance the security, compatibility, and functionality of the django-pgcrypto-fields library.

[jdanielnd]

@peterfarrell is there any chance this PR gets merged? We’re actively using django-pgcrypto and would benefit from the Decimal field update.