Description of problem:
This a separate bug for the leftover issue of bug 2211961:

When editing a host group, changing the life cycle environment automatically sets the "PXE loader" value to "PXELinux BIOS" on the Operating System tab.

Version-Release number of selected component (if applicable):
foreman-3.5.1.18-1.el8sat.noarch

How reproducible:
100%

Steps to Reproduce:
1. Create host group

[Host Group] tab
Host group: <hgtest>
Life cycle environment: <lcetest>
Content View: <ccvrhel8>
Content Source: <satellite.example.org>

[Network]
Domain: <example.org>
IPv4 Subnet: <mysubnet>

[Operating System]
Architecture: x86_64
Operating System: RedHat 8.3
Media selection: All Media
Media: <RHEL83UEFI>
Partition Table: Kickstart default
PXE loader: PXELinux UEFI

[Locations] and [Organisations]
mylocation
myorg

2. Edit 'hgtest' and change the Lifecycle Environment field to a different value. Note: the Content View field becomes unset so remember to set it back.

[Host Group] tab
Life cycle environment: <lceprod>
Content View: <ccvrhel8>

3. Before submitting the above change, check the [Operating System] tab.

Actual results:
[Operating System] tab
PXE loader: PXELinux BIOS

Expected results:
PXE loader: PXELinux UEFI

Additional info:
After talking to @aruzicka@redhat.com , we decided to track the leftover issue in 6.13 bug 2211961 separately as this bug and it is meant to be fixed only in the 6.13 version!
Fixing the issue in 6.14+ is handled in bug 1955046