New packages: qt6

[Johnnynator]

TOOD:

• Address TODOs

the cmake part does not use the host version of some tools e.g. a problem with lconvert fixed with 6.1.0

[ci skip]

[ericonr]

Missing libatomic from armv6l. Do you know why armv6l doesn't get this error, only armv6l-musl?

[Johnnynator]

Missing libatomic from armv6l. Do you know why armv6l doesn't get this error, only armv6l-musl?

armv6l does error, you just didn't see it, since CI doesn't run for armv6l

[yopito]

I had a look on qt6-base and cmake and ccache. here my points:

"-D-DQT_USE_CCACHE" has no effect if ccache is enabled from xbps-src : ccache will be used.
I think "-DQT_USE_CCACHE=OFF" might be a better idea (similar to other packages)

qt6-base build uses precompiled headers (pch) when working with automoc. ccache does not handle pch until some additional configuration (see https://ccache.dev/manual/4.2.1.html#_precompiled_headers).
=> so ccache is rather useless in this case: about 150/1160 "objects" are stored in ccache
workarounds:

• hope that packagers will enable pch support in ccache. IMHO, this support is somewhat imprecise, afraid of false positive
• disable use of pch for building qt6-base with "-DBUILD_WITH_PCH=OFF" : some overhead (not that much) on first build, but ccache efficiency after (about 70 minutes on 1st run, 6 minutes then to build+package qt6-base). And no specific ccache settings is needed