ci: install yarn in image

docker/Dockerfile

@@ -70,11 +70,11 @@ RUN git config --global init.defaultBranch main
 SHELL ["/usr/bin/fish", "--command"]
 
 RUN set -Ua fish_user_paths \
+    $HOME/.proto/shims \
     $HOME/.cargo/bin \
     $HOME/.local/bin \
     $HOME/.moon/bin \
-    $HOME/.proto/bin \
-    $HOME/.proto/shims
+    $HOME/.proto/bin
 
 RUN curl -fsSL https://moonrepo.dev/install/moon.sh | bash && moon --version
 RUN curl -fsSL https://moonrepo.dev/install/proto.sh | bash && proto --version
@@ -83,6 +83,6 @@ RUN mkdir -p ~/.config/fish/completions
 RUN moon completions --shell fish > ~/.config/fish/completions/moon.fish
 RUN proto completions --shell fish > ~/.config/fish/completions/proto.fish
 
-RUN proto install bun && proto install node && proto install npm
+RUN proto install bun && proto install node && proto install npm && proto install yarn
 
 RUN sudo pacman -Scc --noconfirm