[ci] Add macos15 builds

Author: dpiparo

.github/workflows/root-ci-config/buildconfig/mac15.txt

@@ -0,0 +1,34 @@
+builtin_cfitsio=ON
+builtin_cppzmq=ON
+builtin_davix=ON
+builtin_fftw3=ON
+builtin_freetype=ON
+builtin_ftgl=ON
+builtin_gl2ps=ON
+builtin_glew=ON
+builtin_gsl=ON
+builtin_gtest=ON
+builtin_lz4=ON
+builtin_lzma=ON
+builtin_nlohmannjson=ON
+builtin_pcre=ON
+builtin_openssl=ON
+builtin_tbb=ON
+builtin_vc=ON
+builtin_vdt=ON
+builtin_veccore=ON
+builtin_xrootd=ON
+builtin_xxhash=ON
+builtin_zeromq=ON
+builtin_zstd=ON
+ccache=ON
+cocoa=ON
+fortran=OFF
+mysql=OFF
+pgsql=OFF
+pythia8=OFF
+test_distrdf_dask=ON
+test_distrdf_pyspark=ON
+tmva-cpu=OFF
+tmva-sofie=ON
+x11=OFF

.github/workflows/root-ci.yml

@@ -100,6 +100,9 @@ jobs:
             arch: ARM64
             overrides: ["LLVM_ENABLE_ASSERTIONS=On", "builtin_zlib=ON"]
           - platform: mac14
+            arch: X64
+            overrides: ["LLVM_ENABLE_ASSERTIONS=On", "CMAKE_CXX_STANDARD=20"]
+          - platform: mac15
             arch: ARM64
             overrides: ["LLVM_ENABLE_ASSERTIONS=On", "CMAKE_CXX_STANDARD=20"]
           - platform: mac-beta