pc-bios: remove obsolete linuxboot.bin prebuilt blob

The corresponding source was removed in commit 88641f4df388faa78c49c54ed885e530fd0a75dc Author: Philippe Mathieu-Daudé <philmd@linaro.org> Date: Thu Jan 8 11:30:39 2026 +0800 hw/i386: Remove linuxboot.bin We must also remove the pre-built blob to avoid a GPL violation from lack of complete & corresponding source. Signed-off-by: Daniel P. Berrangé <berrange@redhat.com> Message-ID: <20260324122025.892666-1-berrange@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Signed-off-by: Thomas Huth <thuth@redhat.com>