Remove spurious includes from sinpif_test.cpp

MPFR functionality is provided by the MPFRWrapper instead, and the direct "mpfr.h" inclusion is not needed - this test doesn't rely on it (similar to its sibling libc/test/src/math/exhaustive/cospif_test.cpp that doesn't have it).

Author: vonosmas

libc/test/src/math/exhaustive/sinpif_test.cpp

@@ -7,10 +7,8 @@
 //===----------------------------------------------------------------------===//
 
 #include "exhaustive_test.h"
-#include "mpfr.h"
 #include "src/math/sinpif.h"
 #include "utils/MPFRWrapper/MPFRUtils.h"
-#include <sys/types.h>
 
 namespace mpfr = LIBC_NAMESPACE::testing::mpfr;