lib/types: Allow paths as submodule values

lib/tests/modules.sh

@@ -174,8 +174,7 @@ checkConfigOutput "true" config.submodule.inner ./declare-submoduleWith-modules.
 checkConfigOutput "true" config.submodule.outer ./declare-submoduleWith-modules.nix
 
 ## Paths should be allowed as values and work as expected
-# Temporarily disabled until https://github.com/NixOS/nixpkgs/pull/76861
-#checkConfigOutput "true" config.submodule.enable ./declare-submoduleWith-path.nix
+checkConfigOutput "true" config.submodule.enable ./declare-submoduleWith-path.nix
 
 cat <<EOF
 ====== module tests ======

lib/types.nix

@@ -392,14 +392,16 @@ rec {
           else unify (if shorthandOnlyDefinesConfig then { config = value; } else value);
 
         allModules = defs: modules ++ imap1 (n: { value, file }:
-          # Annotate the value with the location of its definition for better error messages
-          coerce (lib.modules.unifyModuleSyntax file "${toString file}-${toString n}") value
+          if isAttrs value || isFunction value then
+            # Annotate the value with the location of its definition for better error messages
+            coerce (lib.modules.unifyModuleSyntax file "${toString file}-${toString n}") value
+          else value
         ) defs;
 
       in
       mkOptionType rec {
         name = "submodule";
-        check = x: isAttrs x || isFunction x;
+        check = x: isAttrs x || isFunction x || path.check x;
         merge = loc: defs:
           (evalModules {
             modules = allModules defs;