update test to auto detect system compiler

tests.py

@@ -147,10 +147,11 @@ def test_install_environment(tmp_path):
     with open(module_file,'w') as f:
         f.write(lines)
 
-    # Replace gcc@10.2.1 with gcc#13.1.1 for testing on laptop
+    # Replace gcc@10.2.1 with gcc#13.1.1 or available system gcc for testing on laptop
+    gcc_ver = subprocess.run(['gcc -dumpfullversion'],shell=True,capture_output=True).stdout.decode('utf-8').strip()
     setup_file = release_base_dir / "spack-environments/spack_setup.sh"
     with open(setup_file,'r') as f:
-        lines = f.read().replace('system_compiler="gcc@10.2.1"','system_compiler="gcc@13.1.1"')
+        lines = f.read().replace('system_compiler="gcc@10.2.1"',f'system_compiler="gcc@{gcc_ver}"')
     with open(setup_file,'w') as f:
         f.write(lines)
     # install global_generic toolchain