What were you trying to do that didn't work?

macros.kmp: lookup for latest_kernel is slow and it is always run.

If the kernel_version is defined, there is no need to lookup the latest
kernel*-devel package version. 
If it's not defined, we can only look for the relevant packages instead of using rpm -qa.

Customer is using rpmspec to list the generated rpms and generating make target on the fly, so running `rpm -qa` on each kmod spec slows down quite a bit the process.

Issue is present on RHEL 9.4 as well:
-------------------------------------

1. cat /usr/lib/rpm/macros.d/macros.kmp  | grep kernel_version -C2
       %global kmod_release %{-r*}%{!-r:%{release}} \
       %global latest_kernel %({ rpm -q --qf '%% {VERSION}

   -%%{RELEASE}.%%{ARCH}\\\\n' `rpm -qa | egrep "^kernel(-rt|-aarch64)?-devel" | /usr/lib/rpm/redhat/rpmsort -r | head -n 1`; echo '%%%%{nil}'; } | head -n 1) \
       %{!?kernel_version:%

   Unknown macro: {expand}

   \
       %global kverrel %(%{kmodtool} verrel %{?kernel_version} 2>/dev/null) \
       flavors="default" \
       if [ -z "%*" ]; then \
   -------------------------------------

kernel-rpm-macros-185-13.el9.noarch was used on my test system.

How reproducible:
Always

Steps to Reproduce:
1. Customer is using a spec file with kernel_module_package and kernel_version defined.

Actual results:
last_kernel runs because it's a %global
Also last_kernel uses `rpm -qa` which is pretty slow

Expected results:
When kernel_version is defined, last_kernel doesn't run

Additional info:
1. We can speed up last_kernel with something like
```
rpm q --qf '%{VERSION}%{RELEASE}.%{ARCH}\n' kernel-rt-devel kernel-aarch64-devel kernel-devel | /usr/lib/rpm/redhat/rpmsort -r 2>/dev/null | head -n1
```
We can also move it and make it a %define instead of a %global so it doesn't run when not used

2. Customer had filed 2108441 against fedora long back.