fix: pnpm install

Dockerfile

@@ -94,10 +94,7 @@ RUN rye toolchain register /usr/bin/python \
     && rye toolchain register /usr/bin/pypy
 
 RUN fish -c 'SHELL=/usr/bin/fish pnpm setup' \
-    && fish -c 'SHELL=/usr/bin/fish pnpm -g add pnpm'
-
-RUN fish -c 'SHELL=/usr/bin/fish pnpm setup' \
-    && fish -c 'SHELL=/usr/bin/fish pnpm -g add pnpm'
+    && fish -c 'SHELL=/usr/bin/fish pnpm self-update'
 
 RUN mkdir -p /home/mzwing/.config/code-server/ \
     && touch /home/mzwing/.config/code-server/config.yaml \