YUM update fails with error regarding /boot disk space

Symptoms

When running the 'yum update' command in the terminal, the following error is displayed.

Error Summary
-------------
Disk Requirements:
  At least 42MB more space needed on the /boot filesystem. 

Cause

System packages cannot be updated due to a full /boot partition. Commonly, that partition may become full due to multiple old kernels persisting on the system. By default, the system may keep up to 3 old kernels installed inside the /boot partition.

Resolution

1. Access the server's command line as the 'root' user via SSH or "Terminal" in WHM.

2. Run the following command.

   - CentOS 7 or CloudLinux 6/7:

   package-cleanup --oldkernels --count=2

   - CloudLinux 8/9, AlmaLinux 8/9, or Rocky Linux 8/9:

   dnf remove --oldinstallonly --setopt installonly_limit=2 kernel