some tests fail in 9.11 if newer bind.keys file is installed
System tests that don't specify dnssec-validation yes
or bindkeys-file
in their configurations will try to open the installed bind.keys
file, and in 9.11 they fail because trust-anchors
isn't recognized.
In other branches this doesn't cause test failures but it should be cleaned up anyway; there's no good reason for a test to access installed files.