Don't use M_PI from libc.math

It's not part of the C standard, and not provided on Windows. Fix for
src/sage/plot/plot3d/shapes.cp311-win_amd64.pyd.p/src/sage/plot/plot3d/shapes.pyx.c:12624:35: error: 'M_PI' undeclared (first use in this function)
12624 |   __pyx_t_3 = PyLong_FromDouble(((M_PI * __pyx_v_self->radius) / __pyx_v_ds)); if (unlikely(!__pyx_t_3)) __PYX_ERR(0, 959, __pyx_L1_error)

Author: tobiasdiez

src/sage/plot/plot3d/shapes.pyx

@@ -51,14 +51,14 @@ EXAMPLES::
 #                  https://www.gnu.org/licenses/
 # ****************************************************************************
 
-from libc.math cimport sqrt, sin, cos, acos, M_PI
+from libc.math cimport sqrt, sin, cos, acos
 from sage.rings.real_double import RDF
 from sage.modules.free_module_element import vector
 from sage.misc.decorators import rename_keyword
 from sage.plot.plot3d.base import Graphics3dGroup
 from sage.plot.plot3d.index_face_set cimport IndexFaceSet, PrimitiveObject
 from sage.plot.plot3d.transform cimport point_c
-
+from sage.arith.constants cimport M_PI
 
 # Helper function to check that Box input is right
 def validate_frame_size(size):

src/sage/stats/hmm/chmm.pyx

@@ -18,7 +18,8 @@ AUTHOR:
 # ***************************************************************************
 
 from cpython.object cimport PyObject_RichCompare
-from libc.math cimport log, sqrt, exp, isnormal, isfinite, M_PI
+from libc.math cimport log, sqrt, exp, isnormal, isfinite
+from sage.arith.constants cimport M_PI
 cdef double sqrt2pi = sqrt(2*M_PI)
 from cysignals.signals cimport sig_on, sig_off