fickling's `platform` module subprocess invocation evades `check_safety()` with `LIKELY_SAFE`

Our assessment We added platform to the blocklist of unsafe modules https://github.com/trailofbits/fickling/commit/351ed4d4242b447c0ffd550bb66b40695f3f9975. It was not possible to inject extra arguments to file without first monkey-patching platform.followsymlinks with the pickle, as it always...