docs(python): Update version switcher for 1.0.0 final release (#16848)

Author: stinodego

py-polars/docs/source/_static/version_switcher.json

@@ -5,15 +5,15 @@
     "url": "https://docs.pola.rs/api/python/dev/"
   },
   {
-    "name": "1",
+    "name": "1 (stable)",
     "version": "1",
-    "url": "https://docs.pola.rs/api/python/version/1/"
+    "url": "https://docs.pola.rs/api/python/stable/",
+    "preferred": true
   },
   {
-    "name": "0.20 (stable)",
+    "name": "0.20",
     "version": "0.20",
-    "url": "https://docs.pola.rs/api/python/stable/",
-    "preferred": true
+    "url": "https://docs.pola.rs/api/python/version/0.20/"
   },
   {
     "name": "0.19",