ci: Don't set `compiler-builtins-no-f16-f128` #2907

Job	Run time
duplicates	9s
spell_check	8s
build_system	26s
build (gcc-15.deb, --test-libcore)	1m 16s
build (gcc-15.deb, --std-tests)	1m 53s
build (gcc-15.deb, --extended-regex-example-tests)	1m 2s
build (gcc-15.deb, --extended-regex-tests)	1m 4s
build (gcc-15.deb, --extended-rand-tests)	1m 5s
build (gcc-15.deb, --projects)	1m 16s
build (gcc-15-without-int128.deb, --std-tests)	1m 6s
build (gcc-15.deb, --test-successful-rustc --nb-parts 2 --current-part 1)	1m 3s
build (gcc-15-without-int128.deb, --extended-regex-example-tests)	59s
build (gcc-15-without-int128.deb, --test-libcore)	1m 4s
build (gcc-15-without-int128.deb, --projects)	1m 45s
build (gcc-15.deb, --test-successful-rustc --nb-parts 2 --current-part 0)	1m 2s
build (gcc-15-without-int128.deb, --extended-rand-tests)	1m 8s
build (gcc-15-without-int128.deb, --test-successful-rustc --nb-parts 2 --current-part 0)	2m 17s
build (gcc-15-without-int128.deb, --test-successful-rustc --nb-parts 2 --current-part 1)	2m 34s
build (gcc-15-without-int128.deb, --extended-regex-tests)	1m 54s
success	2s
	23m 13s

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