Adjust terminology in PR template to match GitHub interface

committer != author (which I think is a distinction Git itself makes)

Author: YoshiRulz

.github/pull_request_template.md

@@ -7,4 +7,4 @@
 [//]: # "Apart from the mandatory license signature, these tasks are optional, but doing them could save reviewers some time and get the PR merged sooner."
 Check if completed:
 - [ ] I have run any relevant test suites
-- [ ] I, the committer, have read the [licensing terms for contributors](https://github.com/TASEmulators/BizHawk/blob/master/contributing.md#copyrights-and-licensing) (last updated 2024-06-22) and am compliant
+- [ ] I, the commit author, have read the [licensing terms for contributors](https://github.com/TASEmulators/BizHawk/blob/master/contributing.md#copyrights-and-licensing) (last updated 2024-06-22) and am compliant