Edit flatpak.md

[sspencerwire]

• Reword the admonition for to be for 8.x only
• remove easily from conclusion

Author checklist (Completed by original Author)

• Good fit for the Rocky Linux project? Title and Author Metatags inserted ?
• If applicable, steps and instructions have been tested to work
• Initial self-review to fix basic typos and grammar completed

Rocky Documentation checklist (Completed by Rocky team)

• 1st Pass (Document is good fit for project and author checklist completed)
• 2nd Pass (Technical Review - check for technical correctness)
• 3rd Pass (Detailed Editorial Review and Peer Review)
• Final approval (Final Review)

[github-actions]

Test results for bbd0dde:

Number of broken URLs: 6

URL,RESULT,FILENAME
 http://example.org/foo.txt,failed,books/web_services/052-load-balancer-proxies-varnish.md
 https://www.virtualbox.org/,failed,guides/automation/templates-automation-packer-vsphere.md
 http://0.0.0.0:61208/,failed,guides/network/glances_network_monitoring.md
 https://www.virtualbox.org/wiki/Downloads,failed,guides/virtualization/vbox-rocky.md
 https://www.atomicorp.com/installers/atomic,failed,guides/web/apache_hardened_webserver/ossec-hids.md
 https://your.domain.name/install.php,failed,guides/cms/chyrp_lite.md