feat(zkvmLib): Ability to add an extra Cargo.lock

Adds the ability to specify an `extraLockfile` attribute in args. Its
value should evaluate to a string path. It's included in the beginning,
so it overshadows dependencies, which are specified in the other
Cargo.lock files.

Must be added to commonArgs (i.e. to both `buildDepsOnly` and
`buildPackage` args).

Author: Syndamia

zkvmLib.nix

@@ -68,7 +68,13 @@ pkgs: guest: let
           mkdir -p "$out"
           cd zkvms/${args.pname}
 
+        '' + (if args ? extraLockfile then ''
+          cat ${args.extraLockfile} > lockfile
+          tail -n +4 ./host/Cargo.lock >> lockfile
+        '' else ''
           cat ./host/Cargo.lock > lockfile
+        '') + ''
+
           tail -n +4 ./guest/Cargo.lock >> lockfile
           tail -n +4 ../../guests/${guest}/Cargo.lock >> lockfile