update-cpm script

Signed-off-by: crueter <crueter@eden-emu.dev>

tools/update-cpm.sh

@@ -1,6 +1,16 @@
 #!/bin/sh -e
 
-# SPDX-FileCopyrightText: Copyright 2025 Eden Emulator Project
+# SPDX-FileCopyrightText: Copyright 2025 crueter
 # SPDX-License-Identifier: GPL-3.0-or-later
 
-wget -O CMakeModules/CPM.cmake https://github.com/cpm-cmake/CPM.cmake/releases/latest/download/CPM.cmake
+# updates CPMUtil, its docs, and related tools from the latest release
+
+if command -v zstd > /dev/null; then
+    EXT=tar.zst
+else
+    EXT=tar.gz
+fi
+
+wget "https://git.crueter.xyz/CMake/CPMUtil/releases/download/continuous/CPMUtil.$EXT"
+tar xf "CPMUtil.$EXT"
+rm "CPMUtil.$EXT"