Periodic distribution update to supported_distros.py.example

[pleia2]

Once #258 and openmainframeproject/software-discovery-tool-data#76 are resolved and merged, update the src/config/supported_distros.py.example file to reflect the correct distributions shipped with the data repository.

[pleia2]

While we're making these edits, I noticed there's a slight inconsistency in the actual z/OS sources we have.

We should do the following:

Remove:
'z/OS from IBM-Z-zOS': 'IBM_Z_zOS'
Add
'z/OS from Ambitus': 'ZOS_Ambitus'

[pleia2]

@vmuralictr See my comment above about adjusting the z/OS sources as well, but we can do that in another PR.