Change PyPy version to rebuild cache

Author: Vladimir Safonkin

.github/workflows/e2e-cache.yml

@@ -61,7 +61,7 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest, windows-latest, macos-latest]
-        python-version: ['3.9', 'pypy-3.7-v7.x']
+        python-version: ['3.9', 'pypy-3.8']
     steps:
       - uses: actions/checkout@v3
       - name: Install poetry