chore: use pnpm for github action

.github/workflows/unit-tests.yml

@@ -1,12 +1,40 @@
 name: Unit Tests
-on: push
+on:
+  - push
+  - pull_request
+
 jobs:
-  build:
+  cache-and-install:
     runs-on: ubuntu-latest
+
     steps:
-      - uses: actions/checkout@v2
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - uses: pnpm/action-setup@v4
+        name: Install pnpm
+        with:
+          run_install: false
+
+      - name: Install Node.js
+        uses: actions/setup-node@v4
+        with:
+          cache: 'pnpm'
+
+      - name: Get pnpm store directory
+        shell: bash
+        run: |
+          echo "STORE_PATH=$(pnpm store path --silent)" >> $GITHUB_ENV
+
+      - uses: actions/cache@v4
+        name: Setup pnpm cache
+        with:
+          path: ${{ env.STORE_PATH }}
+          key: ${{ runner.os }}-pnpm-store-${{ hashFiles('**/pnpm-lock.yaml') }}
+          restore-keys: |
+            ${{ runner.os }}-pnpm-store-
 
-      - name: Install packages
+      - name: Install dependencies
         run: pnpm install
 
       - name: Run unit tests