chore: remove nox uninstall/reinstall from python build.sh template (#490)

Source-Link: googleapis/synthtool@2635888
Post-Processor: gcr.io/cloud-devrel-public-resources/owlbot-python:latest@sha256:007e7e46ef05e5a32e652bd0062be02f6ff050347d91e0f357b28caab0a042c4

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

Author: gcf-owl-bot[bot]

.github/.OwlBot.lock.yaml

@@ -13,5 +13,5 @@
 # limitations under the License.
 docker:
   image: gcr.io/cloud-devrel-public-resources/owlbot-python:latest
-  digest: sha256:98f3afd11308259de6e828e37376d18867fd321aba07826e29e4f8d9cab56bad
-# created: 2024-02-27T15:56:18.442440378Z
+  digest: sha256:007e7e46ef05e5a32e652bd0062be02f6ff050347d91e0f357b28caab0a042c4
+# created: 2024-03-15T14:27:15.879623611Z

.kokoro/build.sh

@@ -33,13 +33,6 @@ export GOOGLE_APPLICATION_CREDENTIALS=${KOKORO_GFILE_DIR}/service-account.json
 # Setup project id.
 export PROJECT_ID=$(cat "${KOKORO_GFILE_DIR}/project-id.json")
 
-# Remove old nox
-python3 -m pip uninstall --yes --quiet nox-automation
-
-# Install nox
-python3 -m pip install --upgrade --quiet nox
-python3 -m nox --version
-
 # If this is a continuous build, send the test log to the FlakyBot.
 # See https://github.com/googleapis/repo-automation-bots/tree/main/packages/flakybot.
 if [[ $KOKORO_BUILD_ARTIFACTS_SUBDIR = *"continuous"* ]]; then