chore(python): update dependencies in .kokoro/requirements.txt (#466)

Source-Link: googleapis/synthtool@e3a1277
Post-Processor: gcr.io/cloud-devrel-public-resources/owlbot-python:latest@sha256:452901c74a22f9b9a3bd02bce780b8e8805c97270d424684bff809ce5be8c2a2

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

packages/google-cloud-python-speech/noxfile.py

@@ -277,7 +277,11 @@ def docs(session):
     """Build the docs for this library."""
 
     session.install("-e", ".")
-    session.install("sphinx==4.0.1", "alabaster", "recommonmark")
+    session.install(
+        "sphinx==4.0.1",
+        "alabaster",
+        "recommonmark",
+    )
 
     shutil.rmtree(os.path.join("docs", "_build"), ignore_errors=True)
     session.run(
@@ -300,7 +304,10 @@ def docfx(session):
 
     session.install("-e", ".")
     session.install(
-        "sphinx==4.0.1", "alabaster", "recommonmark", "gcp-sphinx-docfx-yaml"
+        "sphinx==4.0.1",
+        "alabaster",
+        "recommonmark",
+        "gcp-sphinx-docfx-yaml",
     )
 
     shutil.rmtree(os.path.join("docs", "_build"), ignore_errors=True)