Fix typo in pull request template

[hmaarrfk]

Before you submit a pull request, check that it meets these guidelines:

1. The pull request should include tests.
2. If the pull request adds functionality, the docs should be updated. Put
   your new functionality into a function with a docstring, and add the
   feature to the list in README.rst.
3. The pull request should work for Python 3.9, 3.10 and 3.11.

[GPUtester]

Can one of the admins verify this patch?

Admins can comment ok to test to allow this one PR to run or add to allowlist to allow all future PRs from the same author to run.

[jakirkham]

add to allowlist

[jakirkham]

Thanks Mark! 🙏