chore: Update stream-chat-css target branch

Author: szuperaz

.github/workflows/workflow.yml

@@ -70,7 +70,7 @@ jobs:
           fetch-depth: "0"
           repository: GetStream/stream-chat-css
           path: stream-chat-css
-          ref: fix-sdk-specific
+          ref: theming2
       - name: Copy docs from stream-chat-css
         env:
           DOCS_SOURCE: stream-chat-css/docs