Update PCK embedding SCons warning message to mention mold linker

mold is now part of the SCons `linker` option.

(cherry picked from commit 074d87d7188da6400028c719ea7571bff6265c36)

platform/x11/detect.py

@@ -424,7 +424,7 @@ def configure(env):
         gnu_ld_version = re.search("^GNU ld [^$]*(\d+\.\d+)$", linker_version_str, re.MULTILINE)
         if not gnu_ld_version:
             print(
-                "Warning: Creating template binaries enabled for PCK embedding is currently only supported with GNU ld, not gold or LLD."
+                "Warning: Creating export template binaries enabled for PCK embedding is currently only supported with GNU ld, not gold, LLD or mold."
             )
         else:
             if float(gnu_ld_version.group(1)) >= 2.30: