IVGCVSW-7854 Remove/rewrite asserts in the backends unit tests.

* Replace calls to ARMNN_ASSERT with DOCTEST CHECK.

Signed-off-by: Colm Donelan <colm.donelan@arm.com>
Change-Id: I8904d169b2099d57a344e319b2f14cf5d8392ae8
diff --git a/src/backends/cl/test/ClDefaultAllocatorTests.cpp b/src/backends/cl/test/ClDefaultAllocatorTests.cpp
index 411a480..24b8a09 100644
--- a/src/backends/cl/test/ClDefaultAllocatorTests.cpp
+++ b/src/backends/cl/test/ClDefaultAllocatorTests.cpp
@@ -1,5 +1,5 @@
 //
-// Copyright © 2021, 2023 Arm Ltd and Contributors. All rights reserved.
+// Copyright © 2021, 2023-2024 Arm Ltd and Contributors. All rights reserved.
 // SPDX-License-Identifier: MIT
 //
 
@@ -97,7 +97,7 @@
     // Initialize Mock Backend
     MockBackendInitialiser initialiser;
     auto factoryFun = BackendRegistryInstance().GetFactory(MockBackend().GetIdStatic());
-    ARMNN_ASSERT(factoryFun != nullptr);
+    CHECK(factoryFun != nullptr);
     auto backend = factoryFun();
     auto defaultAllocator = backend->GetDefaultAllocator();