ci: install poetry

Author: zaro0508

.github/workflows/main.yaml

@@ -15,5 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
+      - name: Install Poetry
+        uses: snok/install-poetry@v1
       - name: run pre-commit
         run: poetry run pre-commit run --all-files --show-diff-on-failure