Do not build custom build profiles anymore

This change removes the custom build profiles from the CI pipeline.
Previously, this repository offered kernels that were specifically
compiled for a certain microarchitecture.

However, since the effect of such optimizations for the kernel is rather
neglible and due to the increased cost of maintaining several build profiles,
I have decided to stop offering these as pre-builts.

.github/workflows/release.yml

@@ -16,12 +16,6 @@ jobs:
           - build_profile: 'generic'
             build_cc: gcc-10
             build_cflags: ''
-          - build_profile: zen2
-            build_cc: gcc-10
-            build_cflags: '-march=znver2'
-          - build_profile: cascadelake
-            build_cc: gcc-10
-            build_cflags: '-march=cascadelake'
     steps:
     - name: Clean Workspace
       run: rm -rf *.deb *.ddeb *.build *.buildinfo *.changes