Fix tensor backend with copy

Context

Following aidge_core!273 (merged) (see aidge_core#207 (closed)), fix Tensor copy from a different backend in TensorImpl unit-test.

unit_tests/CMakeLists.txt

@@ -3,7 +3,7 @@ Include(FetchContent)
 FetchContent_Declare(
   Catch2
   GIT_REPOSITORY https://github.com/catchorg/Catch2.git
-  GIT_TAG        v3.0.1 # or a later release
+  GIT_TAG        v3.7.1 # or a later release
 )
 
 FetchContent_MakeAvailable(Catch2)