build(deps): bump jinja2 from 3.1.4 to 3.1.6 in /.kokoro

Bumps [jinja2](https://github.com/pallets/jinja) from 3.1.4 to 3.1.6.
- [Release notes](https://github.com/pallets/jinja/releases)
- [Changelog](https://github.com/pallets/jinja/blob/main/CHANGES.rst)
- [Commits](pallets/jinja@3.1.4...3.1.6)

---
updated-dependencies:
- dependency-name: jinja2
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.kokoro/requirements.txt

@@ -285,9 +285,9 @@ jeepney==0.8.0 \
     # via
     #   keyring
     #   secretstorage
-jinja2==3.1.4 \
-    --hash=sha256:4a3aee7acbbe7303aede8e9648d13b8bf88a429282aa6122a993f0ac800cb369 \
-    --hash=sha256:bc5dd2abb727a5319567b7a813e6a2e7318c39f4f487cfe6c89c6f9c7d25197d
+jinja2==3.1.6 \
+    --hash=sha256:0137fb05990d35f1275a587e9aee6d56da821fc83491a0fb838183be43f66d6d \
+    --hash=sha256:85ece4451f492d0c13c5dd7c13a64681a86afae63a5f347908daf103ce6d2f67
     # via gcp-releasetool
 keyring==25.2.1 \
     --hash=sha256:2458681cdefc0dbc0b7eb6cf75d0b98e59f9ad9b2d4edd319d18f68bdca95e50 \