Document start header --- is removed when setting head comment

[solidDoWant]

Describe the bug

When calling head_comment, the document header is always removed.

Version of yq: 4.44.3
Operating system: linux
Installed via: container image

Input Yaml
Concise yaml document(s) (as simple as possible to show the bug, please keep it to 10 lines or less)
data1.yml:

---
this: should really work

Command
The command you ran:

yq '. head_comment="Example"' data1.yml

Here's a single line command to reproduce this example: printf -- '---\nthis: should really work\n' | yq '. head_comment="Example"'

Actual behavior

# Example
this: should really work

Expected behavior

---
# Example
this: should really work

Additional context
Seems to be another instance of these bugs:

• yq e removes '---' header #1462
• yq -d removes '---' header #351