[GitHub CI] Clear unused NDKs and iOS simulator to fix iOS CI

Summary: This diff applies the changes from D13247 to the iOS GitHub Actions CI jobs.

Test Plan: I landed the changes to ios_ci.yml directly on master and confirmed that the GitHub Actions run succeeded: https://github.com/CommE2E/comm/actions/runs/10725587415/job/29743758905

Reviewers: varun, will

Reviewed By: will

Subscribers: tomek

Differential Revision: https://phab.comm.dev/D13249