[ci] migrate CI steps to local nix shell

Use the local nix shell for the CI steps that can be migrated. Some of
the build steps could be refactored further by using the argopkgs "real
package".
12 jobs for nix-shell in 7 minutes and 1 second (queued for 3 seconds)
Status Job ID Name Coverage
  Style
passed #68379
kvm nix
clang-format

00:00:06

passed #68381
nix kvm
repoquality

00:02:50

passed #68375
nix kvm
style:docs

00:00:29

failed #68374
nix kvm
clang-format

00:00:01

failed #68373
nix kvm
repoquality

00:00:03

failed #68380
kvm nix
repoquality

00:00:01

 
  Build
passed #68376
nix kvm
make:generic

00:01:15

passed #68378
knl
make:knl

00:02:49

passed #68384
kvm nix
make:out-of-tree

00:00:44

failed #68382
kvm nix
make:out-of-tree

00:00:01

failed #68383
nix kvm
make:out-of-tree

00:00:01

failed #68377
nix kvm
make:out-of-tree

00:00:01