[Ruby] remove #include <sys/time.h> (#34178)

#34168

Closes #34178

COPYBARA_INTEGRATE_REVIEW=https://github.com/grpc/grpc/pull/34178 from alto-ruby:no-sys-time-h 42c5ad0f79
PiperOrigin-RevId: 590223092

src/ruby/ext/grpc/rb_grpc.c

@@ -23,7 +23,6 @@
 #include <math.h>
 #include <ruby/vm.h>
 #include <stdbool.h>
-#include <sys/time.h>
 #include <sys/types.h>
 #include <unistd.h>
 

src/ruby/ext/grpc/rb_grpc.h

@@ -21,8 +21,6 @@
 
 #include <ruby/ruby.h>
 
-#include <sys/time.h>
-
 #include <grpc/support/time.h>
 
 /* grpc_rb_mGrpcCore is the module containing the ruby wrapper GRPC classes. */