Update CONTRIBUTING.md (encode#9095)

Removed apostrophe from "it's".

CONTRIBUTING.md

@@ -1,6 +1,6 @@
 # Contributing to REST framework
 
-At this point in it's lifespan we consider Django REST framework to be essentially feature-complete. We may accept pull requests that track the continued development of Django versions, but would prefer not to accept new features or code formatting changes.
+At this point in its lifespan we consider Django REST framework to be essentially feature-complete. We may accept pull requests that track the continued development of Django versions, but would prefer not to accept new features or code formatting changes.
 
 Apart from minor documentation changes, the [GitHub discussions page](https://github.com/encode/django-rest-framework/discussions) should generally be your starting point. Please only raise an issue or pull request if you've been recommended to do so after discussion.