Test

Adding GCC15 to CI #112

Job	Run time
container (gcc:15.1, true)	56s
build (windows-latest, true)	1m 34s
build (ubuntu-latest, gcc, 13)	35s
build (ubuntu-24.04, gcc, 14, true)	53s
build (ubuntu-latest, gcc, 12)	37s
build (ubuntu-latest, gcc, 11)	1m 36s
build (macos-latest)	34s
build (ubuntu-latest, clang, 19, true)	1m 13s
build (ubuntu-latest, clang, 18, true)	1m 5s
build (ubuntu-22.04, clang, 14)	45s
build (ubuntu-latest, clang, 17)	51s
build (ubuntu-22.04, clang, 13)	50s
build (ubuntu-22.04, clang, 15)	47s
build (ubuntu-latest, clang, 20, true)	1m 8s
build (ubuntu-22.04, clang, 16)	52s
	14m 16s

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