fix: properly cache poetry deps

.github/workflows/instance_test.yml

@@ -21,7 +21,7 @@ jobs:
         uses: actions/setup-python@v4
         with:
           python-version: ${{matrix.python-version}}
-          cache: 'pip'
+          cache: 'poetry'
 
       - name: Install and setup redis
         run: |

.github/workflows/mypy.yml

@@ -20,7 +20,7 @@ jobs:
       uses: actions/setup-python@v4
       with:
         python-version: ${{matrix.python-version}}
-        cache: 'pip' # caching pip dependencies
+        cache: 'poetry'
 
     - name: Install dependencies
       run: |