Deprecate legacy libarm_compute_core

This library is an artifact of Compute Library's legacy library architecture and no longer serves any purpose.

Users must no longer link their applications to this library and instead link only to the main `libarm_compute` library to maintain full functionality.

Resolves: COMPMID-6300

Change-Id: I7c222f511174ce9b0cfde94cf8f90da4a89f2a8b
Signed-off-by: Jakub Sujak <jakub.sujak@arm.com>
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/9760
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Pablo Marquez Tello <pablo.tello@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Benchmark: Arm Jenkins <bsgcomp@arm.com>
diff --git a/SConscript b/SConscript
index 320cb2d..be062e1 100644
--- a/SConscript
+++ b/SConscript
@@ -31,6 +31,9 @@
 import json
 import codecs
 
+print("DEPRECATION NOTICE: Legacy libarm_compute_core has been deprecated. Link your application only to "
+      "libarm_compute for core library functionality")
+
 VERSION = "v0.0-unreleased"
 LIBRARY_VERSION_MAJOR = 31
 LIBRARY_VERSION_MINOR =  0