fix action

Author: TomTasche

.github/workflows/ios_main.yml

@@ -21,13 +21,17 @@ jobs:
         run: rm '/usr/local/bin/2to3'
       - name: ninja
         run: brew install ninja
+
       # https://stackoverflow.com/a/57758679/198996
       - name: bundler
         run: gem install bundler:1.17.3
       - name: fastlane
         run: bundle install
+
+      - name: pip
+        run: python3 -m ensurepip
       - name: conan
-        run: python3 -m ensurepip && pip install conan
+        run: pip install conan
 
       - name: run tests
         run: bundle exec fastlane tests