Add "brew update"

Author: yuki-koyama

.github/workflows/macos-python.yml

@@ -25,7 +25,7 @@ jobs:
     - name: install-test-dependencies
       run: |
         pip install matplotlib pillow seaborn scipy
-        brew install font-linux-biolinum
+        brew update && brew install font-linux-biolinum
     - name: test
       run: |
         python ./python-examples/bayesian-optimization.py