test(ios, e2e): use pod install run script vs manual commands

the manual commands don't remove Podfile.lock so when you bump versions
you get conflicts, and it's easy to forget when bumping versions so then
e2e tests fail.

Author: mikehardy

.github/workflows/tests_e2e.yml

@@ -281,7 +281,7 @@ jobs:
           timeout_minutes: 10
           retry_wait_seconds: 60
           max_attempts: 3
-          command: cd tests/ios && pod install
+          command: yarn tests:ios:pod:install
 
       - name: Build iOS App
         run: |