perf(pulumi): allow disabling upwards discovery (#4159)

* perf(pulumi): disable upwards discovery by default

* change `search_upwards` default to `true`

.github/config-schema.json

@@ -1026,6 +1026,7 @@
       "default": {
         "disabled": false,
         "format": "via [$symbol($username@)$stack]($style) ",
+        "search_upwards": true,
         "style": "bold 5",
         "symbol": " ",
         "version_format": "v${raw}"
@@ -3831,6 +3832,10 @@
         "disabled": {
           "default": false,
           "type": "boolean"
+        },
+        "search_upwards": {
+          "default": true,
+          "type": "boolean"
         }
       }
     },