util/apcb: Use python3 for apcb_edit.py

The code was written on a workstation that has python
pointing to python3.

BUG=b:157140753
TEST=Built trembyle and was able to boot to the OS

Signed-off-by: Raul E Rangel <rrangel@chromium.org>
Change-Id: I181d87aad1ffb10e12f8ffd7513318f6d6bcbc3f
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41739
Reviewed-by: Rob Barnes <robbarnes@google.com>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

util/apcb/apcb_edit.py

@@ -1,4 +1,4 @@
-#! /usr/bin/env python
+#!/usr/bin/env python3
 
 # Script for editing APCB binaries, such as injecting SPDs and GPIO
 # configurations.