Do not require man pages to be present in test script

[yubiuser]

What does this PR aim to accomplish?:

We allow the installer to continue installation even when mandb or the man directory is not present.

pi-hole/automated install/basic-install.sh

Lines 1421 to 1429 in 21026d9

	printf " %b Testing man page installation" "${INFO}"
	if ! is_command mandb ; then
	# if mandb is not present, no manpage support
	printf "%b %b man not installed\\n" "${OVER}" "${INFO}"
	return
	elif [[ ! -d "/usr/local/share/man" ]]; then
	# appropriate directory for Pi-hole's man page is not present
	printf "%b %b man pages not installed\\n" "${OVER}" "${INFO}"
	return

However, in the test suite, we only allow to skip the test for the man files in case mandb is not present

pi-hole/test/test_any_automated_install.py

Lines 211 to 213 in 21026d9

	maninstalled = True
	if (info_box + " man not installed") in install.stdout:
	maninstalled = False

pi-hole/test/test_any_automated_install.py

Lines 291 to 320 in 21026d9

	if maninstalled is True:
	check_man = test_cmd.format("x", "/usr/local/share/man", piholeuser)
	actual_rc = host.run(check_man).rc
	assert exit_status_success == actual_rc
	check_man = test_cmd.format("r", "/usr/local/share/man", piholeuser)
	actual_rc = host.run(check_man).rc
	assert exit_status_success == actual_rc
	check_man = test_cmd.format("x", "/usr/local/share/man/man8", piholeuser)
	actual_rc = host.run(check_man).rc
	assert exit_status_success == actual_rc
	check_man = test_cmd.format("r", "/usr/local/share/man/man8", piholeuser)
	actual_rc = host.run(check_man).rc
	assert exit_status_success == actual_rc
	check_man = test_cmd.format("x", "/usr/local/share/man/man5", piholeuser)
	actual_rc = host.run(check_man).rc
	assert exit_status_success == actual_rc
	check_man = test_cmd.format("r", "/usr/local/share/man/man5", piholeuser)
	actual_rc = host.run(check_man).rc
	assert exit_status_success == actual_rc
	check_man = test_cmd.format(
	"r", "/usr/local/share/man/man8/pihole.8", piholeuser
	)
	actual_rc = host.run(check_man).rc
	assert exit_status_success == actual_rc
	check_man = test_cmd.format(
	"r", "/usr/local/share/man/man8/pihole-FTL.8", piholeuser
	)
	actual_rc = host.run(check_man).rc
	assert exit_status_success == actual_rc
	# check not readable sudoers file

This PR allows to skip the man test also when the man directory (/usr/local/share/man) is not present.

Discovered while working on #5027

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[dschaper]

Thank you for the awesomely detailed PR notes and commit message!!

[pralor-bot]

This pull request has been mentioned on Pi-hole Userspace. There might be relevant details there:

https://discourse.pi-hole.net/t/pi-hole-ftl-v5-20-1-web-v5-18-1-and-core-v5-15-released/60495/1