Updating enum43 to support Python3 versions

Description

This will save us from the following error

```PYTHON
AttributeError: module 'enum' has no attribute 'IntFlag'
```

Done

Assignee

Sandy Student

Reporter

Open Source Pull Request Bot

Contributor Name

Ahmed Jazzar

Repo

edx/edx-val

Customer

Epic Link

None

OSCM Assignee

None

Platform Map Area (Levels 1 & 2)

None

Platform Map Area (Levels 3 & 4)

None

Blended Hour Utilization Percentage

None

edX Theme

None

edX Squad

None

Github Lines Added

None

Github Lines Deleted

None

Story Points

0.5

Priority

Unset