ci: update workflow names to be more descriptive

Update the workflow names in GitHub Actions to better reflect

.github/workflows/build.yml

@@ -1,4 +1,4 @@
-name: Build Script
+name: Kernel Build Process
 permissions:
   contents: write
   actions: write 

.github/workflows/main.yml

@@ -1,4 +1,4 @@
-name: Build GKI
+name: Build Kernels
 
 permissions:
   contents: write