Update from github-actions[bot] running command 'prdoc'

Author: github-actions[bot]

prdoc/pr_10359.prdoc

@@ -0,0 +1,10 @@
+title: Remove invulnerables form staking-async
+doc:
+- audience: Runtime Dev
+  description: |-
+    The 'staking-async' pallet has inherited the list of invulnerable validators from the 'staking' pallet, but these are no longer used. We can therefore remove them, together with additional clean-up.
+crates:
+- name: asset-hub-westend-runtime
+  bump: major
+- name: pallet-staking-async
+  bump: major