fix: POC for a sane dracut chroot environment

[haraldh]

bash and various other utilities only work with a sane chroot
environment. At least bash needs /dev/fd to function properly.

Take this as a POC patch to make things work.

See https://bugzilla.redhat.com/show_bug.cgi?id=1962975#c2

With this patch:

# lsinitrd ./isolinux/initrd.img|fgrep ca-bundle
-r--r--r--   1 root     root       216090 May 18 10:36 etc/pki/ca-trust/extracted/pem/tls-ca-bundle.pem
lrwxrwxrwx   1 root     root           46 May 18 10:36 etc/pki/tls/certs/ca-bundle.crt -> ../../ca-trust/extracted/pem/tls-ca-bundle.pem

[coveralls]

Pull Request Test Coverage Report for Build 864338747

• 0 of 4 (0.0%) changed or added relevant lines in 1 file are covered.
• 2 unchanged lines in 1 file lost coverage.
• Overall coverage decreased (-0.03%) to 41.829%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/pylorax/treebuilder.py	0	4	0.0%

Files with Coverage Reduction	New Missed Lines	%
src/pylorax/treebuilder.py	2	37.26%

Totals
Change from base Build 814822323:	-0.03%
Covered Lines:	1290
Relevant Lines:	2894

---

💛 - Coveralls

[bcl]

Thanks for tracking that down, I've expanded on this a bit in #1151 which should make it easier to add future requirements.