Set a maximum duration for iOS 15 tests (#4229)

We are not sure why but iOS 15 tests get sometimes stuck re-running
forever (see
https://app.circleci.com/pipelines/github/RevenueCat/purchases-ios/21864/workflows/7af8697c-aad3-4e1f-92ae-f55186a72f27/jobs/254961).
It looks like rerunning fixes it.

Until we find out what's up, we are going to set a max time for this
job. CircleCI recommends setting a sleep and calling an API to cancel
the job when that finishes
https://support.circleci.com/hc/en-us/articles/14114124583195-How-to-set-a-custom-maximum-job-duration

.circleci/config.yml

@@ -92,6 +92,20 @@ aliases:
         only: main
 
 commands:
+  set-maximum-duration:
+    parameters:
+      seconds:
+        type: integer
+        default: 600
+    steps:
+      - run:
+          name: Set maximum job duration to << parameters.seconds >> seconds
+          background: true
+          command: |
+            sleep << parameters.seconds >>
+            curl --request POST \
+            --url https://circleci.com/api/v2/project/gh/$CIRCLE_PROJECT_USERNAME/$CIRCLE_PROJECT_REPONAME/job/$CIRCLE_BUILD_NUM/cancel \
+            --header "Circle-Token: $CIRCLECI_API_TOKEN"
   install-runtime:
     parameters:
       runtime-name:
@@ -678,6 +692,7 @@ jobs:
 
     steps:
       - checkout
+      - set-maximum-duration
       - install-dependencies:
           install_swiftlint: false
       - update-spm-installation-commit