Clad issues with `MacOSX15.0.sdk`

[hahnjo]

After https://github.com/root-project/root/pull/15900, there should be four failing tests due to Clad:

The following tests FAILED:
        206 - gtest-math-mathcore-test-CladDerivatorTests (Failed)
        232 - gtest-roofit-histfactory-test-testHistFactory (Failed)
        235 - gtest-roofit-hs3-test-testRooFitHS3 (Failed)
        267 - gtest-roofit-roofitcore-test-testRooFuncWrapper (Failed)

They seem somehow related to __builtin_pow. For this reason, to keep green builds, clad was disabled for mac-beta in https://github.com/root-project/root/pull/15910.

Reproducer

Install MacOSX15.0.sdk, build ROOT and try to run all tests.

ROOT version

master

Installation method

build from source

Operating system

macOS