* build: fix native_mksnapshot build
When we changed our electron_mksnapshot_zip target to include the v8_context_snapshot_generator, this dependency made the `run_mksnapshot` target run which was trying to run an arm/arm64 binary on x64 hardware.
Don't use custom build args for native_mksnapshot as they are not needed
* Added comment on why snapshot_blob.bin is skipped on arm/arm64