CI: test against Julia 1.11-rc1

Author: fingolfin

.github/workflows/CI.yml

@@ -26,6 +26,7 @@ jobs:
           - '1.6'
           - '1.9'
           - '~1.10.0-0'
+          - '~1.11.0-0'
           - 'nightly'
         julia-arch:
           - x64