devel/electron{32,33}: mark as BROKEN on aarch64 platform

In file included from ../../third_party/unrar/src/crypt.cpp:1:
In file included from ../../third_party/unrar/src/rar.hpp:6:
../../third_party/unrar/src/os.hpp:167:10: fatal error: 'asm/hwcap.h' file not found

167 | #include <asm/hwcap.h>
    |          ^~~~~~~~~~~~~

1 error generated.

Reported by: Mark Millard <marklmi@yahoo.com> (via ports@)