chore: move vscode local out of experiments (#5773)

We've been dogfooding the VS Code extension for a while,
and it seems stable enough that it's overall positive
to release!

coderd/apidoc/swagger.json

@@ -346,7 +346,7 @@
             "schema": {
               "type": "array",
               "items": {
-                "$ref": "#/definitions/codersdk.Experiment"
+                "type": "string"
               }
             }
           }
@@ -5464,11 +5464,6 @@
         }
       }
     },
-    "codersdk.Experiment": {
-      "type": "string",
-      "enum": ["vscode_local"],
-      "x-enum-varnames": ["ExperimentVSCodeLocal"]
-    },
     "codersdk.Feature": {
       "type": "object",
       "properties": {