MAINT: Add missing noexcept to shuffle helpers

These shouldn't fail and should work without the GIL, but as cython
points out (now), this doesn't work in practice, because without
the `noexcept`, cython will grab the GIL to check for errors every
time.

Author: seberg

numpy/random/_generator.pyx

@@ -63,7 +63,7 @@ cdef int64_t _safe_sum_nonneg_int64(size_t num_colors, int64_t *colors):
 cdef inline void _shuffle_raw_wrap(bitgen_t *bitgen, np.npy_intp n,
                                    np.npy_intp first, np.npy_intp itemsize,
                                    np.npy_intp stride,
-                                   char* data, char* buf) nogil:
+                                   char* data, char* buf) noexcept nogil:
     # We trick gcc into providing a specialized implementation for
     # the most common case, yielding a ~33% performance improvement.
     # Note that apparently, only one branch can ever be specialized.
@@ -76,7 +76,7 @@ cdef inline void _shuffle_raw_wrap(bitgen_t *bitgen, np.npy_intp n,
 cdef inline void _shuffle_raw(bitgen_t *bitgen, np.npy_intp n,
                               np.npy_intp first, np.npy_intp itemsize,
                               np.npy_intp stride,
-                              char* data, char* buf) nogil:
+                              char* data, char* buf) noexcept nogil:
     """
     Parameters
     ----------
@@ -107,7 +107,7 @@ cdef inline void _shuffle_raw(bitgen_t *bitgen, np.npy_intp n,
 
 
 cdef inline void _shuffle_int(bitgen_t *bitgen, np.npy_intp n,
-                              np.npy_intp first, int64_t* data) nogil:
+                              np.npy_intp first, int64_t* data) noexcept nogil:
     """
     Parameters
     ----------