Site edit page fails to load with a very large number of ASNs assigned

[jeremystretch]

NetBox Edition

NetBox Community

NetBox Version

v4.5.5

Python Version

3.12

Steps to Reproduce

1. Create a RIR
2. Create a site named "Site 1"
3. Create 10,000 ASNs and assign them to this site:

rir = ipam.RIR.objects.first()
site = dcim.Site.objects.get(name='Site 1')
asns = [
    ipam.ASN(asn=i, rir=rir) for i in range(1, 10001)
]
ipam.ASN.objects.bulk_create(asns, batch_size=250)
site.asns.set(
    ipam.ASN.objects.all()
)

4. Attempt to edit the site in the NetBox UI

Expected Behavior

The site edit form should render normally.

Observed Behavior

The response times out (or takes exceedingly long). I believe this is due to the overhead required to render the sites multiple-choice form field with so many values pre-populated.