chore: complete google-cloud-speech migration (#16673)

- Reformat with nox
- Enable generation with librarian
- Regenerate with librarian

Author: jskeet

librarian.yaml

@@ -3567,7 +3567,6 @@ libraries:
       - tests/system/__init__.py
       - tests/system/smoke_test.py
       - tests/unit/test_helpers.py
-    skip_generate: true
     python:
       library_type: GAPIC_COMBO
       name_pretty_override: Cloud Speech

packages/google-cloud-speech/.repo-metadata.json

@@ -1,17 +1,16 @@
 {
-  "api_description": "enables easy integration of Google speech recognition technologies into developer applications. Send audio and receive a text transcription from the Speech-to-Text API service.",
-  "api_id": "speech.googleapis.com",
-  "api_shortname": "speech",
-  "client_documentation": "https://cloud.google.com/python/docs/reference/speech/latest",
-  "default_version": "v1",
-  "distribution_name": "google-cloud-speech",
-  "issue_tracker": "https://issuetracker.google.com/savedsearches/559758",
-  "language": "python",
-  "library_type": "GAPIC_COMBO",
-  "name": "speech",
-  "name_pretty": "Cloud Speech",
-  "product_documentation": "https://cloud.google.com/speech-to-text/docs/",
-  "release_level": "stable",
-  "repo": "googleapis/google-cloud-python",
-  "requires_billing": false
+    "api_description": "enables easy integration of Google speech recognition technologies into developer applications. Send audio and receive a text transcription from the Speech-to-Text API service.",
+    "api_id": "speech.googleapis.com",
+    "api_shortname": "speech",
+    "client_documentation": "https://cloud.google.com/python/docs/reference/speech/latest",
+    "default_version": "v1",
+    "distribution_name": "google-cloud-speech",
+    "issue_tracker": "https://issuetracker.google.com/savedsearches/559758",
+    "language": "python",
+    "library_type": "GAPIC_COMBO",
+    "name": "speech",
+    "name_pretty": "Cloud Speech",
+    "product_documentation": "https://cloud.google.com/speech-to-text/docs/",
+    "release_level": "stable",
+    "repo": "googleapis/google-cloud-python"
 }

packages/google-cloud-speech/google/cloud/speech/__init__.py

@@ -18,12 +18,12 @@
 __version__ = package_version.__version__
 
 
+from google.cloud.speech_v1 import SpeechClient
 from google.cloud.speech_v1.services.adaptation.async_client import (
     AdaptationAsyncClient,
 )
 from google.cloud.speech_v1.services.adaptation.client import AdaptationClient
 from google.cloud.speech_v1.services.speech.async_client import SpeechAsyncClient
-from google.cloud.speech_v1 import SpeechClient
 from google.cloud.speech_v1.types.cloud_speech import (
     LongRunningRecognizeMetadata,
     LongRunningRecognizeRequest,