[CI] use cached deepep installation in gb200 CI (#13388)

scripts/ci/ci_install_deepep.sh

@@ -18,12 +18,9 @@ if [ "$ARCH" != "x86_64" ] && [ "$ARCH" != "aarch64" ]; then
     exit 1
 fi
 
-# It seems GB200 ci runner preinstalls some wrong version of deep_ep, so we cannot rely on it.
-if [ "$GRACE_BLACKWELL" != "1" ]; then
-    if python3 -c "import deep_ep" >/dev/null 2>&1; then
-        echo "deep_ep is already installed or importable. Skipping installation."
-        exit 0
-    fi
+if python3 -c "import deep_ep" >/dev/null 2>&1; then
+    echo "deep_ep is already installed or importable. Skipping installation."
+    exit 0
 fi
 
 # Install system dependencies