[ci] Enable VecCore on all platforms

Author: guitargeek

.github/workflows/root-ci-config/buildconfig/global.txt

@@ -25,7 +25,7 @@ builtin_pcre=OFF
 builtin_tbb=OFF
 builtin_unuran=OFF
 builtin_vdt=OFF
-builtin_veccore=OFF
+builtin_veccore=ON
 builtin_xrootd=OFF
 builtin_xxhash=OFF
 builtin_zeromq=ON
@@ -97,7 +97,7 @@ unfold=ON
 unuran=ON
 uring=OFF
 vdt=ON
-veccore=OFF
+veccore=ON
 vecgeom=OFF
 webgui=ON
 win_broken_tests=OFF