BLD: Set scipy latest supported version to 1.15

tox.ini

@@ -2,7 +2,7 @@
 envlist =
     py{39,310,311,312,313}-test{,-all}{,-dev,-latest,-oldest}{,-cov}
     py{39,310,311,312,313}-test-numpy{119,120,121,122,123,124,125,126,20,21,22}
-    py{39,310,311,312,313}-test-scipy{16,17,18,19,110,111,112,113,114}
+    py{39,310,311,312,313}-test-scipy{16,17,18,19,110,111,112,113,114,115}
     py{39,310,311,312,313}-test-astropy{40,41,42,43,50,51,52,53,60,61,70}
     build_docs
     linkcheck
@@ -56,6 +56,7 @@ description =
     scipy112: with scipy 1.12.*
     scipy113: with scipy 1.13.*
     scipy114: with scipy 1.14.*
+    scipy114: with scipy 1.15.*
     astropy40: with astropy 4.0.*
     astropy41: with astropy 4.1.*
     astropy42: with astropy 4.2.*
@@ -92,6 +93,7 @@ deps =
     scipy112: scipy==1.12.*
     scipy113: scipy==1.13.*
     scipy114: scipy==1.14.*
+    scipy114: scipy==1.15.*
 
     astropy40: astropy==4.0.*
     astropy41: astropy==4.1.*
@@ -111,7 +113,7 @@ deps =
 
     latest: astropy==7.0.*
     latest: numpy==2.2.*
-    latest: scipy==1.14.*
+    latest: scipy==1.15.*
 
     oldest: astropy==4.0.*
     oldest: numpy==1.19.*