spec: promote LAYOUTPRINTCONFIG to unstable #3980

Job	Run time
mingw-cmake	7m 16s
mingw	21m 45s
macOS	13m 28s
linux (CFLAGS="-O0 -fno-omit-frame-pointer -fsanitize=address -fno-var-tracking" --disable-bindings)	7m 30s
ppc64-big-endian	7m 1s
linux (CC="clang")	9m 33s
vs2019	4m 53s
linux-cmake	4m 15s
linux (--enable-release)	19m 9s
mips32-big-endian	15m 41s
linux (--enable-gcov --disable-bindings)	14m 42s
vs2019-ninja	4m 24s
linux (--disable-write)	8m 43s
linux (CFLAGS="-O2 -m32" --disable-bindings)	9m 39s
linux (CFLAGS="-O2 -fno-omit-frame-pointer -fsanitize=undefined -fno-var-tracking" --disable-bind...	16m 54s
	2h 44m 53s

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