Add GCC 12.5 for Bullseye #155

Job	Run time
build (linux/amd64, ubuntu-24.04, bullseye, gcc, 12)	5m 32s
build (linux/amd64, ubuntu-24.04, bookworm, gcc, 12)	1m 45s
build (linux/amd64, ubuntu-24.04, bookworm, gcc, 13)	1m 41s
build (linux/amd64, ubuntu-24.04, bookworm, gcc, 14)	1m 54s
build (linux/amd64, ubuntu-24.04, bookworm, gcc, 15)	1m 52s
build (linux/amd64, ubuntu-24.04, bookworm, clang, 16)	1m 45s
build (linux/arm64, ubuntu-24.04-arm, bookworm, gcc, 12)	2m 11s
build (linux/amd64, ubuntu-24.04, bookworm, clang, 20)	1m 43s
build (linux/arm64, ubuntu-24.04-arm, bullseye, gcc, 12)	5m 37s
build (linux/amd64, ubuntu-24.04, bookworm, clang, 17)	1m 41s
build (linux/amd64, ubuntu-24.04, bookworm, clang, 18)	1m 53s
build (linux/amd64, ubuntu-24.04, bookworm, clang, 19)	1m 42s
build (linux/arm64, ubuntu-24.04-arm, bookworm, clang, 16)	2m 16s
build (linux/arm64, ubuntu-24.04-arm, bookworm, gcc, 13)	1m 56s
build (linux/arm64, ubuntu-24.04-arm, bookworm, gcc, 15)	2m 21s
build (linux/arm64, ubuntu-24.04-arm, bookworm, gcc, 14)	2m 14s
build (linux/arm64, ubuntu-24.04-arm, bookworm, clang, 18)	2m 19s
build (linux/arm64, ubuntu-24.04-arm, bookworm, clang, 17)	2m 20s
build (linux/arm64, ubuntu-24.04-arm, bookworm, clang, 19)	1m 59s
build (linux/arm64, ubuntu-24.04-arm, bookworm, clang, 20)	2m 11s
merge	1s
	46m 53s

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