Include Python version in CI cache key (#748)

Fixes #743

The venv cache was shared across all Python versions, causing
conditional dependencies like async-timeout (needed for Python < 3.11)
to be missing when a venv built for 3.11+ was restored for 3.10.

Author: abrookins

.github/workflows/ci.yml

@@ -48,7 +48,7 @@ jobs:
         uses: actions/cache@v4
         with:
           path: .venv
-          key: venv-${{ runner.os }}-${{ hashFiles('**/poetry.lock') }}
+          key: venv-${{ runner.os }}-${{ env.pythonversion }}-${{ hashFiles('**/poetry.lock') }}
       - name: Make sync version of library (redis_om)
         run: make sync
         #----------------------------------------------
@@ -120,7 +120,7 @@ jobs:
         uses: actions/cache@v4
         with:
           path: .venv
-          key: venv-${{ runner.os }}-${{ hashFiles('**/poetry.lock') }}
+          key: venv-${{ runner.os }}-${{ matrix.pyver }}-${{ hashFiles('**/poetry.lock') }}
         #----------------------------------------------
         # Make sync version of library (redis_om)
         #----------------------------------------------