Snapd 2.59 prepare-image not fetching assertions on arm64

Somewhere between snapd 2.58.3 and snapd 2.59 there is a regression introduced regarding fetching assertions/declarations while running snap prepare-image. I have so far only recreated this on arm64, but can do so reliably. I cannot make it happen on amd64, and haven't tried any other architectures.

In the following logs I have used these steps to reproduce this issue:

1) create two identical chroots, preseedjawn and preseedjawn2
2) run snap prepare-image from version 2.58.3 on preseedjawn
3) run snap prepare-image from version 2.59 on preseedjawn2
4) compare the contents of the <chroot>/var/lib/snapd/seed/assertions directories

```
 ubuntu@raspi:~$ snap info snapd
name: snapd
summary: Daemon and tooling that enable snap packages
publisher: Canonical✓
store-url: https://snapcraft.io/snapd
license: GPL-3.0
description: |
  Install, configure, refresh and remove snap packages. Snaps are
  'universal' packages that work across many different Linux systems,
  enabling secure distribution of the latest apps and utilities for
  cloud, servers, desktops and the internet of things.

  Start with 'snap list' to see installed snaps.
type: snapd
snap-id: PMrrV4ml8uWuEUDBT8dSGnKUYbevVhc4
tracking: latest/stable
refresh-date: 2 days ago, at 18:43 UTC
channels:
  latest/stable: 2.58.3 2023-03-20 (18600) 45MB -
  latest/candidate: 2.58.3 2023-03-07 (18600) 45MB -
  latest/beta: 2.59 2023-03-10 (18748) 48MB -
  latest/edge: 2.59+git709.g7dbd962 2023-03-22 (18872) 48MB -
installed: 2.58.3 (18600) 45MB snapd
 ubuntu@raspi:~$ sudo /snap/snapd/18600/usr/bin/snap prepare-image --classic --snap=firefox=latest/stable/ubuntu-23.04 --snap=bare --snap=core22 --snap=snapd --snap=snap-store=latest/stable/ubuntu-23.04 --snap=gtk-common-themes=latest/stable/ubuntu-23.04 --snap=gnome-42-2204=latest/stable/ubuntu-23.04 --snap=snapd-desktop-integration=latest/stable/ubuntu-23.04 --arch=arm64 test-classic.model preseedjawn/
Fetching firefox
firefox 2% 7.70MB/s 28.9sFetching bare
Fetching core22
Fetching snapd
Fetching snap-store
Fetching gtk-common-themes
Fetching gnome-42-2204
Fetching snapd-desktop-integration
 ubuntu@raspi:~$ ls preseedjawn/var/lib/snapd/seed/assertions
16,3wdHCAVyZEmYsCMFDE9qt92UV8rC8Wdk.snap-declaration
16,EISPgh06mRh1vordZY9OZ34QHdd7OrdR.snap-declaration
16,IrwRHakqtzhFRHJOOPxKVPU0Kk7Erhcu.snap-declaration
16,PMrrV4ml8uWuEUDBT8dSGnKUYbevVhc4.snap-declaration
16,amcUKQILKXHHTlmSa7NMdnXSx02dNeeT.snap-declaration
16,gjf3IPXoRiipCu9K0kVu52f0H56fIksg.snap-declaration
16,jZLfBRzf1cYlYysIjD2bwSzNtngY0qit.snap-declaration
16,lATO8HzwVvrAPrlZRAWpfyrJKlAJrZS3.snap-declaration
49jadSjo8x8qkrbA7YkTySJmMm5cKK4HLBT2j8-eryC1c0sYR5xREb4ZW9fpws0t.snap-revision
62rRwo_VHrOdajhLlnNTqUJ8gfWoZZNSFWhxn2AszCKyUAD0d8guxddMFeW5LVKP.snap-revision
BWDEoaqyr25nF5SNCvEv2v7QnM9QsfCc0PBMYD_i2NGSQ32EF2d4D0hqUel3m8ul.account-key
OgeoZuqQpVvSr9eGKJzNCrFGSaKXpkey.account
SI2bNbgfn98zy_t8zwPPDclZH4G_jGOBZG6inoX1VCYrSEyO6lBBPQ3-Xt6JCITU.snap-revision
_e4-wu7p76lfZfnk9D-5uc6mKXNYxMFIW_4O7yf_2hXQEsLRiYWc4OkqyplFeW5r.snap-revision
d-JcZF9nD9eBw7bwMnH61x-bklnQOhQud1Is6o_cn2wTj8EYDi9musrIT9z2MdAa.account-key
ecx0ulPGLHJUbE3jEYcBm_XT4NDYmm7GU5zP_DdQhg-lorbAKwMjIa2zwYoJ7MI5.snap-revision
generic.account
hpKwDJNvb0bpBjpJPecpStgoWmx93Z3oKB8BOMcqnWGG-VAEcyqEDo1lW6w0AJcy.snap-revision
model
olZfDYKrkDShlUIFgp2u72Xd10XY8JBBO9Pi5bqYmSPxuiH5RL25eY8vy4fSt08g.snap-revision
ssqXT1-13QfJ0xfZIq88CkcaPC8vcKrVlgGfBJSBr4WD5RFvxeuQ2E5y9U52VpyX.snap-revision
 ubuntu@raspi:~$ snap info snapd
name: snapd
summary: Daemon and tooling that enable snap packages
publisher: Canonical✓
store-url: https://snapcraft.io/snapd
license: GPL-3.0
description: |
  Install, configure, refresh and remove snap packages. Snaps are
  'universal' packages that work across many different Linux systems,
  enabling secure distribution of the latest apps and utilities for
  cloud, servers, desktops and the internet of things.

  Start with 'snap list' to see installed snaps.
type: snapd
snap-id: PMrrV4ml8uWuEUDBT8dSGnKUYbevVhc4
tracking: latest/beta
refresh-date: today at 21:09 UTC
channels:
  latest/stable: 2.58.3 2023-03-20 (18600) 45MB -
  latest/candidate: 2.58.3 2023-03-07 (18600) 45MB -
  latest/beta: 2.59 2023-03-10 (18748) 48MB -
  latest/edge: 2.59+git709.g7dbd962 2023-03-22 (18872) 48MB -
installed: 2.59 (18748) 48MB snapd
 ubuntu@raspi:~$ sudo /snap/snapd/18748/usr/bin/snap prepare-image --classic --snap=firefox=latest/stable/ubuntu-23.04 --snap=bare --snap=core22 --snap=snapd --snap=snap-store=latest/stable/ubuntu-23.04 --snap=gtk-common-themes=latest/stable/ubuntu-23.04 --snap=gnome-42-2204=latest/stable/ubuntu-23.04 --snap=snapd-desktop-integration=latest/stable/ubuntu-23.04 --arch=arm64 test-classic.model preseedjawn2/
Fetching firefox ({2449})
Fetching bare ({5})
Fetching core22 ({548})
Fetching snapd ({18600})
Fetching snap-store ({937})
Fetching gtk-common-themes ({1535})
Fetching gnome-42-2204 ({66})
Fetching snapd-desktop-integration ({58})
 ubuntu@raspi:~$ ls preseedjawn2/var/lib/snapd/seed/assertions
d-JcZF9nD9eBw7bwMnH61x-bklnQOhQud1Is6o_cn2wTj8EYDi9musrIT9z2MdAa.account-key generic.account model
```

As you can see, with version 2.59 many of the files that should be in assertions are missing. The contents of my model are the genericClassicModel from snapd's asserts/sysdb/generic.go file.