ci: remove llvm-17 variant of the workflow

Also try prettifying the job names.

Signed-off-by: Ihor Solodrai <ihor.solodrai@pm.me>

.github/workflows/vmtest.yml

@@ -29,7 +29,7 @@ on:
         type: string
 jobs:
   vmtest:
-    name: llvm-${{ inputs.llvm-version }} pahole@${{ inputs.pahole }} linux-${{ inputs.kernel }}
+    name: pahole@${{ inputs.pahole }}
     runs-on: ${{ inputs.runs_on }}
     steps: