GitHub Actions for Automating Updates of SPDX Licences and CWE Dictionaries

### Current Behavior

Dependency-Track 4.8.2 was released in April 2023 using SPDX License List v3.11, which was already 17 months old at that time and, more importantly 9 versions out of date (v3.20 was released in February 2023).

This illustrates that we have important data resources that are not updated automatically and this can cause problems for users.

### Proposed Behavior

Set up a scheduled GitHub Actions workflow to create PRs for updating:

* SPDX License List
* CWE Dictionaries

...when new versions are released.

Having a once per week cadence seems appropriate (and can be adjusted later if need be).

### Checklist

- [X] I have read and understand the [contributing guidelines](https://github.com/DependencyTrack/dependency-track/blob/master/CONTRIBUTING.md#filing-issues)
- [X] I have checked the [existing issues](https://github.com/DependencyTrack/dependency-track/issues) for whether this enhancement was already requested