chore: Rotate pubsub token on password change (#7194)

Fixes: https://linear.app/chatwoot/issue/CW-1350/

spec/models/user_spec.rb

@@ -34,6 +34,22 @@ RSpec.describe User do
 
     it { expect(user.pubsub_token).not_to be_nil }
     it { expect(user.saved_changes.keys).not_to eq('pubsub_token') }
+
+    context 'rotates the pubsub_token' do
+      it 'changes the pubsub_token when password changes' do
+        pubsub_token = user.pubsub_token
+        user.password = Faker::Internet.password(special_characters: true)
+        user.save!
+        expect(user.pubsub_token).not_to eq(pubsub_token)
+      end
+
+      it 'will not change pubsub_token when other attributes change' do
+        pubsub_token = user.pubsub_token
+        user.name = Faker::Name.name
+        user.save!
+        expect(user.pubsub_token).to eq(pubsub_token)
+      end
+    end
   end
 
   describe 'hmac_identifier' do