add: Support "xmake clean" and "pkgs"

Author: zhengchenxiao

env.sh

@@ -29,3 +29,6 @@ if ! command -v unzip &> /dev/null; then
 else
     echo "smart-build env ready!"
 fi
+
+export PATH=`python3 -m site --user-base`/bin:$HOME/.env/tools/scripts:$PATH
+export RTT_EXEC_PATH=/usr/bin

models/xmake.lua

@@ -23,7 +23,7 @@
 add_rules("mode.debug", "mode.release")
 
 add_requires("apps")
--- add_requires("rt-thread")
+
 add_requires("xmake::rt-thread", {optional = true})
 
 target("image")