CI: use julia-1.7 (like in pkg compat), disable windows temporarily

Author: marcom

.github/workflows/CI.yml

@@ -18,12 +18,11 @@ jobs:
       fail-fast: false
       matrix:
         version:
-          - '1.6'
+          - '1.7'
           - '1'
         os:
           - ubuntu-latest
           - macOS-latest
-          - windows-latest
         arch:
           - x64
     steps: