Split out postgres schema

schema/v2/dependencies.schema.json

@@ -13,29 +13,7 @@
         "$ref": "platform.schema.json"
       }
     },
-    "postgres": {
-      "description": "Describes the versions of PostgreSQL supported by the package provided by the distribution.",
-      "type": "object",
-      "minProperties": 1,
-      "additionalProperties": false,
-      "properties": {
-        "version": {
-          "description": "A version range identifying the supported versions of PostgreSQL.",
-          "$ref": "version_range.schema.json"
-        },
-        "with": {
-          "description": "The  features that are required to be compiled into PostgreSQL. Each corresponds to the appropriate `--with` configure flag. Omit if the package requires no features.",
-          "type": "array",
-          "items": { "$ref": "term.schema.json" }
-        }
-      },
-      "requires": ["version"],
-      "patternProperties": {
-        "^[xX]_.": {
-          "description": "Custom key"
-        }
-      }
-    },
+    "postgres": { "$ref": "postgres.schema.json" },
     "pipeline": {
       "description": "The build pipeline required to configure, build, test, and install the package provided by the distribution.",
       "enum": [