Description of problem:
clevis-systemd uses ncat in /usr/libexec/clevis-luks-askpass
However, the clevis-systemd RPM has dependency on nc


Not a big issue when only RHEL BaseOs & AppStream repos are in use; however, in EPEL the netcat RPM exists and it too provides nc, but NOT ncat binary clevis-systemd actually uses.


Version-Release number of selected component (if applicable):
clevis-systemd-13-3.el8

How reproducible:
100%

Steps to Reproduce:
1. Look at what the RPM requires

  # rpm -qp --requires rhel-8-for-x86_64-appstream-rpms/Packages/c/clevis- 
 systemd-13-3.el8.x86_64.rpm | head -n 4
  /bin/bash
  /bin/sh
  clevis-luks(x86-64) = 13-3.el8
  nc

2. Looking at script the RPM provides, can see clearly it uses ncat (not nc)

  # grep -n ncat /usr/libexec/clevis-luks-askpass
  60:            echo -n "+$pt" | ncat -U -u --send-only "$s"


3. And can see that nc is provided by both nmap-ncat (AppStream) & netcat (EPEL)

  # dnf --repo rhel-8-for-x86_64-baseos-rpms --repo rhel-8-for-x86_64-appstream-rpms --repo epel whatprovides nc | grep -v @System | grep -B1 Repo
netcat-1.217-3.el8.x86_64 : OpenBSD netcat to read and write data across 
  connections using TCP or UDP
  Repo        : epel
  --
  nmap-ncat-2:7.70-4.el8.x86_64 : Nmap's Netcat replacement
  Repo        : rhel-8-for-x86_64-appstream-rpms
  --
  nmap-ncat-2:7.70-5.el8.x86_64 : Nmap's Netcat replacement
  Repo        : rhel-8-for-x86_64-appstream-rpms


Actual results:
  With netcat from EPEL install (or even selected by dnf when both repos enabled) to meet the 'nc' require, clevis fails and are unable to boot/mount an NBDE system you just installed.

Expected results:
  The requires should match the binary it is using to make sure the actual required binary is installed


Additional info:

  Here can see just nc binary for netcat from EPEL
    # rpm -qp --list ./netcat-1.217-3.el8.x86_64.rpm  | grep bin/nc
    /usr/bin/nc


  And nmap-ncat provides 
    #  rpm -q --list nmap-ncat  | grep bin/nc
    /usr/bin/nc
    /usr/bin/ncat


  Looking at provides, pehaps best to set require on nmap-ncat ... since ncat isn't explicitly listed in provides?

    # rpm -q --provides nmap-ncat
    nc
    nc6
    nmap-ncat = 2:7.70-5.el8
    nmap-ncat(x86-64) = 2:7.70-5.el8