build(deps): bump certifi from 2022.12.7 to 2023.7.22 in /.kokoro (#338)

Bumps [certifi](https://github.com/certifi/python-certifi) from 2022.12.7 to 2023.7.22.
- [Commits](certifi/python-certifi@2022.12.07...2023.07.22)

---
updated-dependencies:
- dependency-name: certifi
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.kokoro/requirements.txt

@@ -20,9 +20,9 @@ cachetools==5.2.0 \
     --hash=sha256:6a94c6402995a99c3970cc7e4884bb60b4a8639938157eeed436098bf9831757 \
     --hash=sha256:f9f17d2aec496a9aa6b76f53e3b614c965223c061982d434d160f930c698a9db
     # via google-auth
-certifi==2022.12.7 \
-    --hash=sha256:35824b4c3a97115964b408844d64aa14db1cc518f6562e8d7261699d1350a9e3 \
-    --hash=sha256:4ad3232f5e926d6718ec31cfc1fcadfde020920e278684144551c91769c7bc18
+certifi==2023.7.22 \
+    --hash=sha256:539cc1d13202e33ca466e88b2807e29f4c13049d6d87031a3c110744495cb082 \
+    --hash=sha256:92d6037539857d8206b8f6ae472e8b77db8058fec5937a1ef3f54304089edbb9
     # via requests
 cffi==1.15.1 \
     --hash=sha256:00a9ed42e88df81ffae7a8ab6d9356b371399b91dbdf0c3cb1e84c03a13aceb5 \
@@ -407,7 +407,7 @@ pygments==2.13.0 \
     # via
     #   readme-renderer
     #   rich
-PyJWT==2.6.0 \
+pyjwt==2.6.0 \
     --hash=sha256:69285c7e31fc44f68a1feb309e948e0df53259d579295e6cfe2b1792329f05fd \
     --hash=sha256:d83c3d892a77bbb74d3e1a2cfa90afaadb60945205d1095d9221f04466f64c14
     # via gcp-releasetool
@@ -495,5 +495,6 @@ zipp==3.8.1 \
     # via importlib-metadata
 
 # WARNING: The following packages were not pinned, but pip requires them to be
-# pinned when the requirements file includes hashes. Consider using the --allow-unsafe flag.
+# pinned when the requirements file includes hashes and the requirement is not
+# satisfied by a package already installed. Consider using the --allow-unsafe flag.
 # setuptools