Install latest PennyLane in CI (#189)

* Install latest PennyLane in CI

* trigger CI

.github/workflows/tests.yml

@@ -10,7 +10,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.9, '3.10', '3.11']
+        python-version: ['3.9', '3.10', '3.11']
 
     steps:
       - name: Cancel Previous Runs
@@ -32,6 +32,7 @@ jobs:
           python -m pip install --upgrade pip
           pip install -r requirements-ci.txt
           pip install qsimcirq
+          pip install --upgrade git+https://github.com/PennyLaneAI/pennylane.git#egg=pennylane
           pip install wheel pytest pytest-cov pytest-mock --upgrade
 
       - name: Install Plugin
@@ -71,6 +72,7 @@ jobs:
           python -m pip install --upgrade pip
           pip install -r requirements-ci.txt
           pip install qsimcirq
+          pip install --upgrade git+https://github.com/PennyLaneAI/pennylane.git#egg=pennylane
           pip install wheel pytest pytest-cov pytest-mock pytest-benchmark flaky --upgrade
 
       - name: Install Plugin