all: Add missing const imports

Found by Ruff checking F821.

Signed-off-by: Angus Gratton <angus@redyak.com.au>

micropython/aiorepl/aiorepl.py

@@ -1,6 +1,7 @@
 # MIT license; Copyright (c) 2022 Jim Mussared
 
 import micropython
+from micropython import const
 import re
 import sys
 import time

micropython/drivers/imu/lsm9ds1/lsm9ds1.py

@@ -44,6 +44,7 @@ while (True):
     time.sleep_ms(100)
 """
 import array
+from micropython import const
 
 
 _WHO_AM_I = const(0xF)

micropython/drivers/sensor/lps22h/lps22h.py

@@ -38,6 +38,7 @@ while (True):
     time.sleep_ms(10)
 """
 import machine
+from micropython import const
 
 _LPS22_CTRL_REG1 = const(0x10)
 _LPS22_CTRL_REG2 = const(0x11)

micropython/mip/mip/__init__.py

@@ -1,6 +1,7 @@
 # MicroPython package installer
 # MIT license; Copyright (c) 2022 Jim Mussared
 
+from micropython import const
 import requests
 import sys
 

micropython/net/webrepl/webrepl.py

@@ -1,6 +1,7 @@
 # This module should be imported from REPL, not run from command line.
 import binascii
 import hashlib
+from micropython import const
 import network
 import os
 import socket