Remove flipper from the codebase.

[bmarty]

The library is not maintained anymore, and we are not using it anymore.

Part of #9086, this is removing these libraries from the (debug) build:

• libcrypto.so
• libevent-2.1.so
• libevent_core-2.1.so
• libevent_extra-2.1.so
• libflipper.so
• libssl.so

[jmartinesp]

Thanks!