ci: Don't set `compiler-builtins-no-f16-f128` #2912

Job	Run time
spell_check	11s
duplicates	3s
build (gcc-15.deb, --test-libcore)	15m 59s
build (gcc-15.deb, --std-tests)	6m 34s
build (gcc-15.deb, --extended-regex-tests)	11m 20s
build (gcc-15-without-int128.deb, --test-successful-rustc --nb-parts 2 --current-part 1)	12m 31s
build (gcc-15-without-int128.deb, --std-tests)	10m 19s
build (gcc-15.deb, --extended-rand-tests)	9m 5s
build (gcc-15-without-int128.deb, --extended-regex-example-tests)	10m 33s
build (gcc-15-without-int128.deb, --test-libcore)	16m 51s
build (gcc-15-without-int128.deb, --projects)	12m 32s
build (gcc-15.deb, --test-successful-rustc --nb-parts 2 --current-part 0)	14m 22s
build (gcc-15-without-int128.deb, --test-successful-rustc --nb-parts 2 --current-part 0)	12m 17s
build (gcc-15.deb, --test-successful-rustc --nb-parts 2 --current-part 1)	11m 22s
build (gcc-15.deb, --projects)	11m 1s
build (gcc-15-without-int128.deb, --extended-rand-tests)	9m 24s
build (gcc-15-without-int128.deb, --extended-regex-tests)	11m 24s
build (gcc-15.deb, --extended-regex-example-tests)	6m 36s
build_system	25s
success	3s
	3h 2m 52s

Provide feedback