Adding STIX data products to list to registered Product attrs

[hayesla]

The STIX data has now been ingested into the SOAR so I've just updated the instrument attrs product so that the data products of STIX can be registered.

[nabobalis]

I pushed a commit adding a changelog entry and fixing the tests hopefully.

Is there anything else we need to do?

[codecov-commenter]

Codecov Report

Patch coverage: 100.00% and no project coverage change.

Comparison is base (9b61c08) 97.17% compared to head (4751ac3) 97.17%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #81 +/- ## ======================================= Coverage 97.17% 97.17% ======================================= Files 4 4 Lines 248 248 ======================================= Hits 241 241 Misses 7 7 ``` | [Impacted Files](https://codecov.io/gh/sunpy/sunpy-soar/pull/81?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=sunpy) | Coverage Δ | | |---|---|---| | [sunpy\_soar/tests/test\_sunpy\_soar.py](https://codecov.io/gh/sunpy/sunpy-soar/pull/81?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=sunpy#diff-c3VucHlfc29hci90ZXN0cy90ZXN0X3N1bnB5X3NvYXIucHk=) | `100.00% <100.00%> (ø)` | | Help us with your feedback. Take ten seconds to tell us [how you rate us](https://about.codecov.io/nps?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=sunpy). Have a feature suggestion? [Share it here.](https://app.codecov.io/gh/feedback/?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=sunpy)

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[hayesla]

Thanks @nabobalis - think this is good to be merged now

[nabobalis]

Done and released as 1.7.