tests: install missing PAM tests

'pam_change_unmounted' and 'pam_recursive' both exist and are referenced
by the test run config, but weren't being installed and so are excluded.
This gets them installed so they will run as expected.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Kay Pedersen <mail@mkwg.de>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Closes #15291