Stop importing pyaudio as soon as the Microphone class is parsed

The import is only used for type checking, so it can instead be put inside an `if TYPE_CHECKING:` block so the optional dependency isn't needed at all times.

Author: Tenzer

deepgram/audio/microphone/microphone.py

@@ -5,12 +5,15 @@
 import inspect
 import asyncio
 import threading
-from typing import Optional, Callable
+from typing import Optional, Callable, TYPE_CHECKING
 import logging
 
 from ...utils import verboselogs
 from .constants import LOGGING, CHANNELS, RATE, CHUNK
 
+if TYPE_CHECKING:
+ import pyaudio
+
 
 class Microphone: # pylint: disable=too-many-instance-attributes
  """
@@ -20,10 +23,8 @@ class Microphone: # pylint: disable=too-many-instance-attributes
  _logger: verboselogs.VerboseLogger
  _exit: threading.Event
 
- import pyaudio # pylint: disable=import-outside-toplevel
-
- _audio: pyaudio.PyAudio
- _stream: pyaudio.Stream
+ _audio: "pyaudio.PyAudio"
+ _stream: "pyaudio.Stream"
  _chunk: int
  _rate: int
  _format: int