Refactor GitHub Actions workflow to improve dependency caching and job structure

Author: coolbeevip

.github/workflows/pr.yml

@@ -45,6 +45,8 @@ jobs:
       - uses: actions/setup-python@v5
         with:
           python-version: '3.9'
+      - name: Install Poetry
+        run: pip install poetry
       - uses: actions/cache@v3
         with:
           path: .venv
@@ -60,6 +62,8 @@ jobs:
       - uses: actions/setup-python@v5
         with:
           python-version: '3.9'
+      - name: Install Poetry
+        run: pip install poetry
       - uses: actions/cache@v3
         with:
           path: .venv