Fix CI.

Author: maleadt

.github/workflows/ci.yml

@@ -14,7 +14,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        version: ['1.6', '^1.7', '^1.8', 'nightly']
+        version: ['1.6', '1.7', '1.8', '1.9', 'nightly']
         os: [ubuntu-latest, macOS-latest, windows-latest]
         arch: [x64]
     steps: