I just dup'd to snapshot 20210425, and picked "solution 3" from the options
below:

Problem: kernel-syms-5.11.16-1.1.x86_64 requires kernel-default-devel =
5.11.16-1, but this requirement cannot be provided
  not installable providers:
kernel-default-devel-5.11.16-1.1.i586[download.opensuse.org-oss]
 Solution 1: deinstallation of kernel-syms-5.11.15-1.2.x86_64
 Solution 2: install kernel-default-devel-5.11.16-1.1.i586 despite the inferior
architecture
 Solution 3: keep obsolete kernel-syms-5.11.15-1.2.x86_64
 Solution 4: break kernel-syms-5.11.16-1.1.x86_64 by ignoring some of its
dependencies

On reboot, uname -r says that I'm still on kernel 5.11.15.  The relevant output
of zypper se - si 'kernel*' says:

i+ | kernel-default              | package | 5.11.15-1.2  | x86_64 | Main
Repository (OSS)
i+ | kernel-default-devel        | package | 5.11.15-1.2  | x86_64 | Main
Repository (OSS)
i+ | kernel-devel                | package | 5.11.15-1.2  | noarch | (System
Packages)
i+ | kernel-devel                | package | 5.11.16-1.1  | noarch | Main
Repository (OSS)

i+ | kernel-macros               | package | 5.11.16-1.1  | noarch | Main
Repository (OSS)
i  | kernel-source               | package | 5.11.15-1.2  | noarch | (System
Packages)
i  | kernel-source               | package | 5.11.16-1.1  | noarch | Main
Repository (OSS)
i+ | kernel-syms                 | package | 5.11.15-1.2  | x86_64 | (System
Packages)

Everything seems to work, but I've never seen a new kernel-syms problem like
this on arrival of a new kernel, so thought I should file a report.