Update iOS versions for running tests on `Runs at night` workflow

[iulianatodoran]

Description

Currently, for running Runs at night workflow in GiHub Actions, the iOS devices are set to use the 14, 15, and 16 iOS versions, and newer versions are available, like 17 and 18. We should update the capabilities from Bindings~\python\tests\integration\conftest.py to include newer versions.

Mocks

Additional info

[iulianatodoran]

✅ Cjecked that the Runs at night workflow in GiHub Actions ran successfully with 17 and 18 iOS versions on devices in BrowserStack

Considering this, I will move the ticket to Done.