python: Only enable basedpyright and ruff by default (#40604)

Though we ship with `basedpyright`, `ruff` and a few other laps for
python, we run them all at once.

Release Notes:

- Only enable `basedpyright` and `ruff` by default when opening Python
files. If you prefer one of the other.

assets/settings/default.json

@@ -1776,7 +1776,8 @@
           "name": "ruff"
         }
       },
-      "debuggers": ["Debugpy"]
+      "debuggers": ["Debugpy"],
+      "language_servers": ["basedpyright", "ruff", "!ty", "!pyrefly", "!pyright", "!pylsp", "..."]
     },
     "Ruby": {
       "language_servers": ["solargraph", "!ruby-lsp", "!rubocop", "!sorbet", "!steep", "..."]