Too many old kernels are installed

Describe the bug Upon inspecting a Clear Linux system today, I noticed that there may be too many old kernels remaining on the system. The system uses kernel-lts exclusively, but there are several kernel bundles actually installed.

Steps to reproduce This problem is not happening on other systems that I've checked. If I discover more concrete steps to reproduce, then I will post them at a later time.

Expected behavior I expected to see older kernels removed from the system as below:

All lts2018 kernels older than latest, since these kernels are no longer used. They stopped being used after kernel-lts switched its bundle include from kernel-lts2018 to kernel-lts2019.
All lts2019 kernels older than latest, except for the currently running lts2019 kernel, if it differs from latest
All native kernels older than latest, since these kernels are not used.
All preempt_rt kernels older than latest, since these kernels are not used.

Environment details

$ uname -r
5.4.32-30.lts2019

$ swupd info | grep version
Installed version: 32840

$ clr-boot-manager version | head -n 1
clr-boot-manager - version 3.2.8

$ sudo swupd bundle-list --quiet | grep '^kernel-'
kernel-install
kernel-lts
kernel-lts2018
kernel-lts2019
kernel-native
kernel-rt

$ tree -shD /boot
/boot
├── [ 512 Feb 12 14:49]  EFI
│   ├── [ 512 Feb 12 14:49]  BOOT
│   │   └── [ 90K Feb 12 14:49]  BOOTX64.EFI
│   └── [2.5K Apr 13 23:53]  org.clearlinux
│       ├── [1.1M Mar 31 23:36]  bootloaderx64.efi
│       ├── [2.9M Mar 11 10:57]  freestanding-00-intel-ucode.cpio
│       ├── [ 15K Mar 11 10:57]  freestanding-i915-firmware.cpio.xz
│       ├── [ 13M Apr  1 23:31]  kernel-org.clearlinux.lts2018.4.19.113-128
│       ├── [ 13M Apr  2 23:31]  kernel-org.clearlinux.lts2018.4.19.114-129
│       ├── [ 13M Apr 12 23:22]  kernel-org.clearlinux.lts2018.4.19.114-130
│       ├── [ 14M Apr  8 23:42]  kernel-org.clearlinux.lts2019.5.4.31-26
│       ├── [ 14M Apr  9 16:27]  kernel-org.clearlinux.lts2019.5.4.31-27
│       ├── [ 14M Apr 12 23:22]  kernel-org.clearlinux.lts2019.5.4.31-29
│       ├── [ 14M Apr 14 10:22]  kernel-org.clearlinux.lts2019.5.4.32-30
│       ├── [ 14M Feb 12 14:49]  kernel-org.clearlinux.native.5.5.3-905
│       ├── [ 14M Apr  8 23:42]  kernel-org.clearlinux.native.5.6.3-935
│       ├── [ 13M Mar 23 00:02]  kernel-org.clearlinux.preempt_rt.5.4.26-58
│       ├── [ 13M Apr  1 23:31]  kernel-org.clearlinux.preempt_rt.5.4.28-61
│       └── [ 90K Mar 31 23:36]  loaderx64.efi
└── [ 512 Apr 13 23:53]  loader
    ├── [1.5K Apr 12 23:22]  entries
    │   ├── [ 532 Apr  1 23:31]  Clear-linux-lts2018-4.19.113-128.conf
    │   ├── [ 532 Apr  2 23:31]  Clear-linux-lts2018-4.19.114-129.conf
    │   ├── [ 532 Apr 12 23:22]  Clear-linux-lts2018-4.19.114-130.conf
    │   ├── [ 550 Apr  8 23:42]  Clear-linux-lts2019-5.4.31-26.conf
    │   ├── [ 550 Apr  9 16:27]  Clear-linux-lts2019-5.4.31-27.conf
    │   ├── [ 550 Apr 12 23:22]  Clear-linux-lts2019-5.4.31-29.conf
    │   ├── [ 550 Apr 14 10:24]  Clear-linux-lts2019-5.4.32-30.conf
    │   ├── [ 544 Feb 12 14:49]  Clear-linux-native-5.5.3-905.conf
    │   ├── [ 549 Apr  8 23:42]  Clear-linux-native-5.6.3-935.conf
    │   ├── [ 548 Mar 23 00:02]  Clear-linux-preempt_rt-5.4.26-58.conf
    │   └── [ 548 Apr  1 23:31]  Clear-linux-preempt_rt-5.4.28-61.conf
    └── [  43 Apr 13 23:53]  loader.conf

5 directories, 28 files

clearlinux / clr-boot-manager

Too many old kernels are installed #232