feat: add Mainframe Software Hub for Linux (linuxonzapps) support

[GREENRAT-K405]

I have added the support for the Mainframe Software Hub for Linux as a new software source in the Software Discovery Tool.

Changes

• bin/package_build.py: New linuxonzapps() function that iterates over all public repos in the linuxonzapps GitHub org via the REST API, collects all release tags, and writes them to linuxonzapps.json
• config/distros.json: Registers "Mainframe Software Hub for Linux" as a new source pointing to the linuxonzapps table

How to run

# to avoid rate limits (optional)
export GITHUB_TOKEN=<your_token>
python3 bin/package_build.py linuxonzapps
node bin/database_build.js

For example:

[GREENRAT-K405]

Hi @pleia2 please have a look. Thanks!

[GREENRAT-K405]

I think the the next step should be to have a github schedule that can automatically fetch periodically.
What do you think @pleia2 please let me know.