[ci] Enable VecCore and Vc in march=native build

This is to show that issues related to VecCore and Vc are fixed, and to
provide much-needed test coverage for a gradual migration from VecCore
and Vc to `std::experimental::simd`.

Author: guitargeek

.github/workflows/root-ci.yml

@@ -402,7 +402,7 @@ jobs:
           - image: alma9
             is_special: true
             property: march_native
-            overrides: ["CMAKE_BUILD_TYPE=RelWithDebInfo", "CMAKE_CXX_FLAGS=-march=native", "CMAKE_C_FLAGS=-march=native", "builtin_zlib=ON", "builtin_zstd=ON", "CMAKE_CXX_STANDARD=20"]
+            overrides: ["CMAKE_BUILD_TYPE=RelWithDebInfo", "CMAKE_CXX_FLAGS=-march=native", "CMAKE_C_FLAGS=-march=native", "builtin_zlib=ON", "builtin_zstd=ON", "CMAKE_CXX_STANDARD=20", "builtin_vc=ON", "builtin_veccore=ON", "vc=ON", "veccore=ON"]
           - image: alma10
             is_special: true
             property: arm64