Fix CI: per-version venv cache, update numpy/lxml for 3.13+3.14

Author: amc-corey-cox

.github/workflows/check-pull-request.yaml

@@ -57,7 +57,7 @@ jobs:
         uses: actions/cache@v4
         with:
           path: .venv
-          key: venv-${{ runner.os }}-${{ hashFiles('**/poetry.lock') }}
+          key: venv-${{ runner.os }}-${{ matrix.python-version }}-${{ hashFiles('**/poetry.lock') }}
 
       #----------------------------------------------
       # install dependencies if cache does not exist