fix(deps): update dependency flake8 to v7

Author: renovate-bot

pyproject.toml

@@ -37,14 +37,14 @@ Changelog = "https://github.com/googleapis/langchain-google-spanner-python/blob/
 [project.optional-dependencies]
 lint = [
     "black[jupyter]==24.8.0",
-    "flake8==6.1.0",
+    "flake8==7.1.1",
     "isort==5.13.2",
 ]
 
 test = [
     "black[jupyter]==24.8.0",
     "bs4==0.0.2",
-    "flake8==6.1.0",
+    "flake8==7.1.1",
     "isort==5.13.2",
     "mypy==1.11.2",
     "pytest==8.3.3",