Fix Redis reusing same property as (#10336)

The collaborationClient getter was incorrectly reusing the same this.client
property as defaultClient, causing it to return the already-initialized
connection to the main Redis instead of creating a new connection to
REDIS_COLLABORATION_URL.

This fix adds a separate private static collabClient property to maintain
a separate connection for collaboration operations.

Co-authored-by: codegen-sh[bot] <131295404+codegen-sh[bot]@users.noreply.github.com>

server/storage/redis.ts

@@ -76,6 +76,7 @@ export default class RedisAdapter extends Redis {
 
   private static client: RedisAdapter;
   private static subscriber: RedisAdapter;
+  private static collabClient: RedisAdapter;
 
   public static get defaultClient(): RedisAdapter {
     return (
@@ -101,8 +102,8 @@ export default class RedisAdapter extends Redis {
    */
   public static get collaborationClient(): RedisAdapter {
     return (
-      this.client ||
-      (this.client = new this(env.REDIS_COLLABORATION_URL, {
+      this.collabClient ||
+      (this.collabClient = new this(env.REDIS_COLLABORATION_URL, {
         connectionNameSuffix: "collab",
       }))
     );