cfl: disable building protobuf library

[ligurio]

The patch disables building protobuf library, this will speed up overall build time significantly.

[ligurio]

/src/lua-c-api-tests/build/tests/capi/external.protobuf_mutator/src/external.protobuf_mutator/src/mutator.cc:90:41: error: no member named 'has_presence' in 'google::protobuf::FieldDescriptor'
   90 |   return !field.is_repeated() && !field.has_presence();
      |                                   ~~~~~ ^
/src/lua-c-api-tests/build/tests/capi/external.protobuf_mutator/src/external.protobuf_mutator/src/mutator.cc:383:15: error: call to non-static member function without an object argument
  383 |   return Any::GetDescriptor() == message->GetDescriptor()
      |          ~~~~~^~~~~~~~~~~~~
/src/lua-c-api-tests/build/tests/capi/external.protobuf_mutator/src/external.protobuf_mutator/src/mutator.cc:389:15: error: call to non-static member function without an object argument
  389 |   return Any::GetDescriptor() == message->GetDescriptor()
      |          ~~~~~^~~~~~~~~~~~~
3 errors generated.

[ligurio]

/src/lua-c-api-tests/build/tests/capi/external.protobuf_mutator/src/external.protobuf_mutator/src/text_format.cc:31:10: error: no member named 'SetRecursionLimit' in 'google::protobuf::TextFormat::Parser'
   31 |   parser.SetRecursionLimit(100);
      |   ~~~~~~ ^
/src/lua-c-api-tests/build/tests/capi/external.protobuf_mutator/src/external.protobuf_mutator/src/text_format.cc:33:10: error: no member named 'AllowUnknownField' in 'google::protobuf::TextFormat::Parser'
   33 |   parser.AllowUnknownField(true);
      |   ~~~~~~ ^
2 errors generated.

[ligurio]

Seems LPM requires newer Protobuf version than packaged on Ubuntu.