Fix errors and warnings identified by `rpmlint`

[psss]

Several errors and warnings were reported by rpmlint in recent Fedora pull requests:

testcloud.noarch: W: only-non-binary-in-usr-lib
testcloud.noarch: W: non-standard-gid /var/lib/testcloud testcloud
testcloud.noarch: W: non-standard-gid /var/lib/testcloud/backingstores testcloud
testcloud.noarch: W: non-standard-gid /var/lib/testcloud/instances testcloud
testcloud.noarch: E: non-standard-dir-perm /var/lib/testcloud 775
testcloud.noarch: E: non-standard-dir-perm /var/lib/testcloud/backingstores 775
testcloud.noarch: E: non-standard-dir-perm /var/lib/testcloud/instances 775
testcloud.noarch: W: non-conffile-in-etc /etc/polkit-1/rules.d/99-testcloud-nonroot-libvirt-access.rules
testcloud.noarch: W: no-manual-page-for-binary t7d
python3-testcloud.noarch: W: no-documentation
python3-testcloud.noarch: E: incorrect-fsf-address /usr/lib/python3.15/site-packages/testcloud-0.12.0.dist-info/licenses/LICENSE
testcloud.noarch: E: incorrect-fsf-address /usr/share/licenses/testcloud/LICENSE
python3-testcloud.noarch: E: explicit-lib-dependency libvirt-daemon
python3-testcloud.noarch: E: explicit-lib-dependency libvirt-daemon-config-network
python3-testcloud.noarch: E: explicit-lib-dependency libvirt-daemon-driver-qemu
python3-testcloud.noarch: E: explicit-lib-dependency libvirt-daemon-driver-storage-core
testcloud.noarch: W: empty-%pre
 3 packages and 1 specfiles checked; 9 errors, 8 warnings, 11 filtered, 9 badness; has taken 0.5 s 
ERROR:run-rpmlint.py:Rpmlint failed!

These are not new and not blocking. Let's get them fixed in the next testcloud release.