Fixed CI workflow to install pnpm before using it

Author: BluePixelDev

.github/workflows/ci.yml

@@ -25,6 +25,9 @@ jobs:
         with:
           node-version: "18"
 
+      - name: Install pnpm
+        run: npm install -g pnpm
+
       - name: Install Dependencies
         run: pnpm install