DOC: edited t_span parameter description in integrate.solve_ivp (#16989)
DOC: edited t_span parameter description in integrate.solve_ivp (#16989)

* DOC: edited t_span parameter description in integrate.solve_ivp

Edited the type description of parameter t_span of integrate.solve_ivp, from "tuple" to "sequence".
Stefan-Endres/scipy,ilayn/scipy,WarrenWeckesser/scipy,ilayn/scipy,andyfaff/scipy,scipy/scipy,andyfaff/scipy,andyfaff/scipy,Stefan-Endres/scipy,ilayn/scipy,mdhaber/scipy,Stefan-Endres/scipy,scipy/scipy,endolith/scipy,Stefan-Endres/scipy,ilayn/scipy,ilayn/scipy,endolith/scipy,WarrenWeckesser/scipy,endolith/scipy,scipy/scipy,mdhaber/scipy,scipy/scipy,andyfaff/scipy,anntzer/scipy,WarrenWeckesser/scipy,anntzer/scipy,ilayn/scipy,mdhaber/scipy,WarrenWeckesser/scipy,anntzer/scipy,endolith/scipy,scipy/scipy,WarrenWeckesser/scipy,mdhaber/scipy,andyfaff/scipy,mdhaber/scipy,anntzer/scipy,mdhaber/scipy,endolith/scipy,anntzer/scipy,andyfaff/scipy,endolith/scipy,Stefan-Endres/scipy,Stefan-Endres/scipy,WarrenWeckesser/scipy,anntzer/scipy,scipy/scipy