This is in anticipation of a mopidyPackages set

This is to avoid mixing python versions in the same plugin closure.

* crystal: 0.31 -> 0.34

* crystal: use latest llvm

* crystal: skip tests for 0.33

* nix-prefetch: 0.3.0 -> 0.3.1

* nix-prefetch: date in man page

* nix-prefetch: use UTC

krita: disable parallel building #35359

mopidy: Create a mopidyPackages set

The patch phase runs after the build phase. Which means than when
using an override to override both 'conf' and 'patches' to provide
a custom config file and apply some patches, it doesn't work:
- first the patches applied (optionally changing config.def.h)
- then preBuild is run which overrides config.def.h with the user
supplied one (effectively cancelling previously applied patches)

By copying the config file in the prePatch phase instead, changes
are kept and applied in order.

* nixos/k3s: simplify config expression

* nixos/k3s: add config assertions and trim unneeded bits

* nixos/k3s: add a test that k3s works; minor module improvements

This is a single-node test. Eventually we should also have a multi-node
test to verify the agent bit works, but that one's more involved.

* nixos/k3s: add option description

* nixos/k3s: add defaults for token/serveraddr

Now that the assertion enforces their presence, we dont' need to use the typesystem for it.

* nixos/k3s: remove unneeded sudo in test

* nixos/k3s: add to test list

R: Update R, CRAN, & Bioconductor

vapoursynth: R48 -> R49