Remove outdated Folds and Functions modules from FiniteMonotonic

specifications. Update manifest.json to reflect these deletions.

Signed-off-by: Markus Alexander Kuppe <github.com@lemmster.de>

Author: lemmy

specifications/FiniteMonotonic/Folds.tla

@@ -58,16 +58,6 @@
       "features": [],
       "models": []
     },
-    {
-      "path": "specifications/FiniteMonotonic/Folds.tla",
-      "features": [],
-      "models": []
-    },
-    {
-      "path": "specifications/FiniteMonotonic/Functions.tla",
-      "features": [],
-      "models": []
-    },
     {
       "path": "specifications/FiniteMonotonic/MCCRDT.tla",
       "features": [