COMPMID-3599 Fix SConstruct compiler version encoding

Signed-off-by: SiCong Li <sicong.li@arm.com>
Change-Id: I314783b7fa01fa6c985d8a57d73379569c1e8dc2
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/4196
Reviewed-by: Michalis Spyrou <michalis.spyrou@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
diff --git a/SConstruct b/SConstruct
index fdb8d5c..5c2e054 100644
--- a/SConstruct
+++ b/SConstruct
@@ -264,7 +264,7 @@
 
 if not GetOption("help"):
     try:
-        compiler_ver = subprocess.check_output(env['CXX'].split() + ["-dumpversion"]).strip()
+        compiler_ver = subprocess.check_output(env['CXX'].split() + ["-dumpversion"]).decode().strip()
     except OSError:
         print("ERROR: Compiler '%s' not found" % env['CXX'])
         Exit(1)