Remove unnecessary include from OperationalSessionSetupPool.h (#32229)

* Remove backwards circular include

* Since we include bits, remove the forward declaration (since now things are not broken anymore due to circularity)

---------

Co-authored-by: Andrei Litvin <andreilitvin@google.com>
diff --git a/src/app/CASESessionManager.h b/src/app/CASESessionManager.h
index 92fb7a9..3e668fa 100644
--- a/src/app/CASESessionManager.h
+++ b/src/app/CASESessionManager.h
@@ -30,8 +30,6 @@
 
 namespace chip {
 
-class OperationalSessionSetupPoolDelegate;
-
 struct CASESessionManagerConfig
 {
     CASEClientInitParams sessionInitParams;
diff --git a/src/app/OperationalSessionSetupPool.h b/src/app/OperationalSessionSetupPool.h
index 583c7e8..30160a1 100644
--- a/src/app/OperationalSessionSetupPool.h
+++ b/src/app/OperationalSessionSetupPool.h
@@ -17,7 +17,6 @@
 
 #pragma once
 
-#include <app/CASESessionManager.h>
 #include <app/OperationalSessionSetup.h>
 #include <lib/support/Pool.h>
 #include <transport/Session.h>