Fix use of WaveFile to support CircuitPython 6.0

Author: theacodes

factory/.cache/firmware.uf2.bin

@@ -1,3 +1,4 @@
 calibrations/
 bootloader.bin
 firmware.uf2
+.cache

factory/.cache/winterbloom_voltageio.py

@@ -2,7 +2,6 @@
 import time
 import os
 import subprocess
-import utils
 import shutil
 import zipfile
 import sys

factory/.gitignore

@@ -23,6 +23,7 @@
 import time
 
 import audioio
+import audiocore
 import board
 import digitalio
 import winterbloom_voltageio
@@ -95,7 +96,7 @@ def released(self):
         return result
 
     def load_sample(self, path):
-        return audioio.WaveFile(open(path, "rb"))
+        return audiocore.WaveFile(open(path, "rb"))
 
     def play(self, sample, pitch_cv=None, loop=False):
         if pitch_cv is not None: