chore(users/Profpatsch): replace Label with pa-label

We upstreamed some of these modules to hackage, so I can get rid of it
here.

Change-Id: I70e1e864a81029cadbbd96cc019a768728431cff
Reviewed-on: https://cl.tvl.fyi/c/depot/+/8659
Reviewed-by: Profpatsch <mail@profpatsch.de>
Tested-by: BuildkiteCI
Autosubmit: Profpatsch <mail@profpatsch.de>
Reviewed-by: sterni <sternenseemann@systemli.org>

users/Profpatsch/my-prelude/default.nix

@@ -7,7 +7,6 @@ pkgs.haskellPackages.mkDerivation {
   src = depot.users.Profpatsch.exactSource ./. [
     ./my-prelude.cabal
     ./MyPrelude.hs
-    ./Label.hs
     ./Pretty.hs
     ./Data/Error/Tree.hs
     ./Aeson.hs
@@ -18,6 +17,7 @@ pkgs.haskellPackages.mkDerivation {
   isLibrary = true;
 
   libraryHaskellDepends = [
+    pkgs.haskellPackages.pa-label
     pkgs.haskellPackages.aeson
     pkgs.haskellPackages.aeson-better-errors
     pkgs.haskellPackages.PyF