Fix template sync over SSH on IPv6

[lpramuk]

Problem Statement

Template sync tests that use SSH for transport are failing on IPv6 while on IPv4 they pass:

    Could not export:
      git '--git-dir=/tmp/d20251201-23437-yapn4p/.git' '--work-tree=/tmp/d20251201-23437-yapn4p' '-c' 'core.quotePath=true' '-c' 'color.ui=false' 'fetch' '--' 'origin'  2>&1
      status: pid 33515 exit 128
      output: "Host key verification failed.\r\nfatal: Could not read from remote repository.\n\nPlease make sure you have the correct access rights\nand the repository exists.\n"

Further investigation showed that ssh-keyscan is used with wrong parameter -4:

[D 251218 12:12:36 hosts:198] <SAT_FQDN> executing command: ssh-keyscan -4 -t rsa -p 50126 infra-podman-ipv6.infra > /usr/share/foreman/.ssh/known_hosts
[D 251218 12:12:36 hosts:200] <SAT_FQDN> command result:
    stdout:
    
    stderr:
    getaddrinfo infra-podman-ipv6.infra: Name or service not known
    
    status: 1

Solution

Sanitize ssh-keyscan command:

• -4 - don't always use ipv4, especially on ipv6
• sudo -u foreman ... - .ssh/known_hosts file should be owned by user foreman not root
• >> {key_path}/known_hosts - .ssh/known_hosts file may contain multiple entries, append new entry

Related Issues

SAT-41275

[lpramuk]

Fixes three problems:

1. -4 - dont always use ipv4, especially on ipv6
2. sudo -u foreman ... - .ssh/known_hosts file should be owned by user foreman not root
3. >> {key_path}/known_hosts - .ssh/known_hosts file may contain multiple entries, append new entry