Fix #884 by avoiding using --pre with pip install in nightly Cirq compatibility checks (#897)

Author: mhucka

.github/workflows/ci-nightly-cirq-test.yaml

@@ -95,7 +95,7 @@ jobs:
         run: |
           echo 'numpy<2.0.0' > constraint.txt
           export PIP_CONSTRAINT=constraint.txt
-          pip install -U cirq --pre
+          pip install --upgrade cirq~=1.0.dev
 
       - name: Configure Bazel options
         run: |