Add PostgreSQL v14 to api spec (#19808)

Author: alanenriqueo

specification/postgresql/resource-manager/Microsoft.DBforPostgreSQL/preview/2022-01-20-preview/postgresql.json

@@ -1461,6 +1461,7 @@
       "type": "string",
       "description": "The version of a server.",
       "enum": [
+        "14",
         "13",
         "12",
         "11"

specification/postgresql/resource-manager/Microsoft.DBforPostgreSQL/preview/2022-03-08-privatepreview/getCachedServerName.json

@@ -126,6 +126,7 @@
       "type": "string",
       "description": "The version of a server.",
       "enum": [
+        "14",
         "13",
         "12",
         "11"