treewide: post-stc-ng test fixes (#340046)

nixos/tests/containers-imperative.nix

@@ -33,6 +33,7 @@ import ./make-test-python.nix ({ pkgs, lib, ... }: {
         stdenv stdenvNoCC emptyContainer.config.containers.foo.path
         libxslt desktop-file-utils texinfo docbook5 libxml2
         docbook_xsl_ns xorg.lndir documentation-highlighter
+        perlPackages.ConfigIniFiles
       ];
     };
 

nixos/tests/installer.nix

@@ -626,6 +626,9 @@ let
             libxslt.bin
             nixos-artwork.wallpapers.simple-dark-gray-bottom
             ntp
+            perlPackages.ConfigIniFiles
+            perlPackages.FileSlurp
+            perlPackages.JSON
             perlPackages.ListCompare
             perlPackages.XMLLibXML
             # make-options-doc/default.nix

pkgs/by-name/sw/switch-to-configuration-ng/package.nix

@@ -10,17 +10,9 @@ rustPlatform.buildRustPackage {
   pname = "switch-to-configuration";
   version = "0.1.0";
 
-  src = lib.fileset.toSource {
+  src = ./src;
-    root = ./.;
-    fileset = lib.fileset.unions [
-      ./Cargo.lock
-      ./Cargo.toml
-      ./build.rs
-      ./src
-    ];
-  };
 
-  cargoLock.lockFile = ./Cargo.lock;
+  cargoLock.lockFile = ./src/Cargo.lock;
 
   nativeBuildInputs = [ pkg-config ];
   buildInputs = [ dbus ];