Use specific chromedriver version

We're having troubles with the setup-chromedriver action failing on
downloading the latest Chromedriver.  This version locks the action
itself, and also version locks the chromedriver.

See nanasess/setup-chromedriver#200 for details.

.github/workflows/build-and-test.yml

@@ -68,7 +68,9 @@ jobs:
 
       - uses: browser-actions/setup-chrome@latest
       - run: chrome --version
-      - uses: nanasess/setup-chromedriver@master
+      - uses: nanasess/setup-chromedriver@v2
+        with:
+          chromedriver-version: '115.0.5790.170'  # https://github.com/nanasess/setup-chromedriver/issues/200
 
       - name: "Set up PostgreSQL"
         uses: harmon758/postgresql-action@v1