[Minor][Test] Clean WASM environment before build (#5759)

diff --git a/tests/scripts/task_web_wasm.sh b/tests/scripts/task_web_wasm.sh
index c68902c..717d328 100755 (executable)
--- a/tests/scripts/task_web_wasm.sh
+++ b/tests/scripts/task_web_wasm.sh
@@ -22,6 +22,7 @@ set -u
 export PYTHONPATH=`pwd`/python
 
 cd web
+make clean
 npm install
 npm run lint
 npm run prepwasm