DBusKeyring is unable to connect to the kwallet service in kloczek's environment

The third class of issues appears to be that the DBusKeyring is unable to connect to the kwallet service:

```
FAILED tests/backends/test_kwallet.py::TestDBusKWallet::test_delete_present - keyring.errors.InitError: Failed to open keyring: org.freedesktop.DBus.Error.ServiceUnknown...
FAILED tests/backends/test_kwallet.py::TestDBusKWallet::test_delete_not_present - keyring.errors.InitError: Failed to open keyring: org.freedesktop.DBus.Error.ServiceUnk...
FAILED tests/backends/test_kwallet.py::TestDBusKWallet::test_delete_one_in_group - keyring.errors.InitError: Failed to open keyring: org.freedesktop.DBus.Error.ServiceUn...
```

```
dbus.exceptions.DBusException: org.freedesktop.DBus.Error.ServiceUnknown: Could not activate remote peer.
```

I don't see that error reported anywhere. @mitya57 do you have any recommendations on how this user can avoid these errors when running the tests (either by improving the viability detection in the backend or by properly configuring the environment to work with the backend)?

_Originally posted by @jaraco in https://github.com/jaraco/keyring/issues/550#issuecomment-981131207_

Start with tests/backends/test_kwallet.py and the DBusKWallet backend, then determine whether the kwallet service can be detected or configured in the reported environment. Done means the failing tests have a defined outcome when the service is unavailable, with the environment requirements or viability behavior documented by the tests.

Written by the indexing model from the issue text.