Remove Storage cron tests from Travis (#5512)

These were ported over to GHA already.

Author: ryanwilson

.travis.yml

@@ -226,18 +226,6 @@ jobs:
       script:
         - travis_retry ./scripts/if_changed.sh ./scripts/pod_lib_lint.rb FirebaseStorage.podspec --skip-tests --platforms=ios
 
-    - stage: test
-      if: type = cron
-      env:
-        - PROJECT=StorageCron METHOD=pod-lib-lint
-      script:
-        - travis_retry ./scripts/pod_lib_lint.rb FirebaseStorage.podspec --use-libraries --skip-tests --platforms=ios
-        - travis_retry ./scripts/pod_lib_lint.rb FirebaseStorage.podspec --use-libraries --skip-tests --platforms=tvos
-        - travis_retry ./scripts/pod_lib_lint.rb FirebaseStorage.podspec --use-libraries --skip-tests --platforms=macos
-        - travis_retry ./scripts/pod_lib_lint.rb FirebaseStorage.podspec --use-modular-headers --skip-tests --platforms=ios
-        - travis_retry ./scripts/pod_lib_lint.rb FirebaseStorage.podspec --use-modular-headers --skip-tests --platforms=tvos
-        - travis_retry ./scripts/pod_lib_lint.rb FirebaseStorage.podspec --use-modular-headers --skip-tests --platforms=macos
-
     - stage: test
       env:
         - PROJECT=Functions METHOD=pod-lib-lint QUICKSTART=Functions