netbox-community-netbox/netbox/templates/dcim/device_component_edit.html

{% extends 'generic/object_edit.html' %}
{% load form_helpers %}

{% block form_fields %}
    {% if form.instance.device %}
        <div class="form-floating mb-3">
            <input class="form-control" value="{{ form.instance.device }}" disabled />
            <label>Device</label>
        </div>
    {% endif %}
    {% render_form form %}
{% endblock %}