chore: [autoapprove] Pin flake8 version (#250)

Source-Link: https://togithub.com/googleapis/synthtool/commit/0ddbff8012e47cde4462fe3f9feab01fbc4cdfd6
Post-Processor: gcr.io/cloud-devrel-public-resources/owlbot-python:latest@sha256:bced5ca77c4dda0fd2f5d845d4035fc3c5d3d6b81f245246a36aee114970082b

Author: gcf-owl-bot[bot]

packages/google-cloud-gke-hub/.github/.OwlBot.lock.yaml

@@ -13,5 +13,5 @@
 # limitations under the License.
 docker:
   image: gcr.io/cloud-devrel-public-resources/owlbot-python:latest
-  digest: sha256:6c1cbc75c74b8bdd71dada2fa1677e9d6d78a889e9a70ee75b93d1d0543f96e1
-# created: 2023-07-25T21:01:10.396410762Z
+  digest: sha256:bced5ca77c4dda0fd2f5d845d4035fc3c5d3d6b81f245246a36aee114970082b
+# created: 2023-08-01T17:41:45.434027321Z

packages/google-cloud-gke-hub/.pre-commit-config.yaml

@@ -26,6 +26,6 @@ repos:
     hooks:
     - id: black
 -   repo: https://github.com/pycqa/flake8
-    rev: 3.9.2
+    rev: 6.1.0
     hooks:
     - id: flake8

packages/google-cloud-gke-hub/noxfile.py

@@ -26,6 +26,7 @@
 
 import nox
 
+FLAKE8_VERSION = "flake8==6.1.0"
 BLACK_VERSION = "black==22.3.0"
 ISORT_VERSION = "isort==5.10.1"
 LINT_PATHS = ["docs", "google", "tests", "noxfile.py", "setup.py"]
@@ -82,7 +83,7 @@ def lint(session):
     Returns a failure if the linters find linting errors or sufficiently
     serious code quality issues.
     """
-    session.install("flake8", BLACK_VERSION)
+    session.install(FLAKE8_VERSION, BLACK_VERSION)
     session.run(
         "black",
         "--check",