Increase minimum Windows test version for saucelabs

Author: robwalch

.github/workflows/build.yml

@@ -352,9 +352,9 @@ jobs:
             ua: chrome
             os: OS X 10.11
             uaVersion: '79.0'
-          - config: chrome-win_7-75.0
+          - config: chrome-win_8-75.0
             ua: chrome
-            os: Windows 7
+            os: Windows 8
             uaVersion: '75.0'
 
     steps: