windows: Update Windows keymap (#37721)

Pickup the changes from #37009

Release Notes:

- N/A

assets/keymaps/default-windows.json

@@ -644,6 +644,7 @@
       "alt-save": "workspace::SaveAll",
       "ctrl-k s": "workspace::SaveAll",
       "ctrl-k m": "language_selector::Toggle",
+      "ctrl-m ctrl-m": "toolchain::AddToolchain",
       "escape": "workspace::Unfollow",
       "ctrl-k ctrl-left": "workspace::ActivatePaneLeft",
       "ctrl-k ctrl-right": "workspace::ActivatePaneRight",
@@ -1075,6 +1076,13 @@
       "tab": "channel_modal::ToggleMode"
     }
   },
+  {
+    "context": "ToolchainSelector",
+    "use_key_equivalents": true,
+    "bindings": {
+      "ctrl-shift-a": "toolchain::AddToolchain"
+    }
+  },
   {
     "context": "FileFinder || (FileFinder > Picker > Editor)",
     "use_key_equivalents": true,