ci: make use of pnpm store cache (#23)

.drone.yml

@@ -6,11 +6,17 @@ name: default
 steps:
   - name: test & build
     image: node:18.16.0-bullseye
+    volumes:
+      - name: pnpm-store-cache
+        path: /drone/.pnpm-store
     commands:
       #   - git config --global --add safe.directory "/drone/src"
-      - npm install -g pnpm
+      - corepack enable # npm i -g pnpm
       - pnpm i --frozen-lockfile
       - pnpm build
+    environment:
+      npm_config_store_dir: /drone/.pnpm-store
+      npm_config_package_import_method: copy
 
   - name: publish
     image: node:18.16.0-bullseye
@@ -28,3 +34,8 @@ steps:
       - (cd dist && zip -r -9 ../um-react.zip .)
       - ./scripts/publish.sh
       - ./scripts/deploy.sh
+
+volumes:
+  - name: pnpm-store-cache
+    host:
+      path: /tmp/.pnpm-store