OpenThread: ClearAllSrpHostAndServices should be guarded with CHIP_DEVICE_CONFIG_ENABLE_THREAD_SRP_CLIENT (#36284)

The code block added in #35065 should be guarded, if the thread stack
manager is not pulled in then this function is not available and breaks
the compilation.
diff --git a/src/platform/OpenThread/GenericNetworkCommissioningThreadDriver.cpp b/src/platform/OpenThread/GenericNetworkCommissioningThreadDriver.cpp
index 0c1d482..fe5bd40 100644
--- a/src/platform/OpenThread/GenericNetworkCommissioningThreadDriver.cpp
+++ b/src/platform/OpenThread/GenericNetworkCommissioningThreadDriver.cpp
@@ -189,6 +189,7 @@
         status = Status::kUnknownError;
     }
 
+#if CHIP_DEVICE_CONFIG_ENABLE_THREAD_SRP_CLIENT
     if (status == Status::kSuccess && ThreadStackMgrImpl().IsThreadAttached())
     {
         Thread::OperationalDataset currentDataset;
@@ -206,6 +207,7 @@
             status = Status::kUnknownError;
         }
     }
+#endif // CHIP_DEVICE_CONFIG_ENABLE_THREAD_SRP_CLIENT
 
     if (status == Status::kSuccess &&
         DeviceLayer::ThreadStackMgrImpl().AttachToThreadNetwork(mStagingNetwork, callback) != CHIP_NO_ERROR)