RHEL autodetection needs more work

[pat-s]

packageVersion("pkgdepends")
[1] ‘0.8.0’

# this worked before
pkgdepends::sysreqs_install_plan("units", config = list(sysreqs_platform = "redhat-9"))$install_scripts
[1] "dnf install -y udunits2-devel"

# as reported from pak::system_r_platform()
pkgdepends::sysreqs_install_plan("units", config = list(sysreqs_platform = "x86_64-pc-linux-gnu-redhat-9.4"))$install_scripts
character(0)

# doesn't work
pkgdepends::sysreqs_install_plan("units", config = list(sysreqs_platform = "rhel-9"))$install_scripts
character(0)

pkgdepends::sysreqs_install_plan("units", config = list(sysreqs_platform = "rhel-9.4"))$install_scripts

character(0)