BUG: Allow write_gcps to succeed without gcp_crs

[peterm790]

• [x] Closes https://github.com/corteva/rioxarray/issues/646
• [ ] Tests added
• [x] Fully documented, including docs/history.rst for all changes and docs/rioxarray.rst for new API

I have not written any tests related to this change.

[snowman2]

Mind adding a test similar to this one with the CRS = None? https://github.com/corteva/rioxarray/blob/205052675b2e2d070a699aa55359806e894e39ec/test/integration/test_integration_rioxarray.py#L2924

[peterm790]

I have added a test, let me know if this is what you had in mind :thumbsup:

[snowman2]

I have added a test, let me know if this is what you had in mind

Looks good :+1:. Once the linting issues are resolved, I think this is ready to merge.

[snowman2]

Suggestion for fixing the linting issues:

python -m pip install pre-commit
pre-commit run --all

[itcarroll]

This PR just made it possible for me to read MODIS data into an xarray.Dataset. Thank you! Logs are expired on the checks, but I hope this can get patched and merged. You are amazing.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 95.99%. Comparing base (ae6635a) to head (2824264). Report is 90 commits behind head on master.

:exclamation: Current head 2824264 differs from pull request most recent head 4f4294b

Please upload reports for the commit 4f4294b to get more accurate results.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #648 +/- ## ========================================== + Coverage 95.90% 95.99% +0.08% ========================================== Files 12 12 Lines 1735 1748 +13 ========================================== + Hits 1664 1678 +14 + Misses 71 70 -1 ```

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[snowman2]

Thanks @peterm790 :+1: