chore: update precommit version and exclude .nox from linting (#144)

* changes without context

        autosynth cannot find the source of changes triggered by earlier changes in this
        repository, or by version upgrades to tools such as linters.

* chore: exclude `.nox` directories from linting

The samples tests create `.nox` directories
with all dependencies installed. These directories
should be excluded from linting.

I've tested this change locally, and it significantly
speeds up linting on my machine.

Source-Author: Tim Swast <[email protected]>
Source-Date: Tue Dec 22 13:04:04 2020 -0600
Source-Repo: googleapis/synthtool
Source-Sha: 373861061648b5fe5e0ac4f8a38b32d639ee93e4
Source-Link: googleapis/synthtool@3738610

Author: yoshi-automation

.flake8

@@ -26,6 +26,7 @@ exclude =
   *_pb2.py
 
   # Standard linting exemptions.
+  **/.nox/**
   __pycache__,
   .git,
   *.pyc,

.pre-commit-config.yaml

@@ -2,7 +2,7 @@
 # See https://pre-commit.com/hooks.html for more hooks
 repos:
 -   repo: https://github.com/pre-commit/pre-commit-hooks
-    rev: v3.3.0
+    rev: v3.4.0
     hooks:
     -   id: trailing-whitespace
     -   id: end-of-file-fixer

synth.metadata

@@ -4,7 +4,7 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/python-logging.git",
-        "sha": "f1e7613c06874691da03b4a19f5ea43e508651a2"
+        "sha": "f81e7a694d24f3ba2ad4380bbf500b8bc463e314"
       }
     },
     {
@@ -19,14 +19,14 @@
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "b670a77a454f415d247907908e8ee7943e06d718"
+        "sha": "373861061648b5fe5e0ac4f8a38b32d639ee93e4"
       }
     },
     {
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "b670a77a454f415d247907908e8ee7943e06d718"
+        "sha": "373861061648b5fe5e0ac4f8a38b32d639ee93e4"
       }
     }
   ],