fix(profiler): remove certificate expiration workaround (#5222)

Author: amchiclet

profiler/kokoro/integration_test.sh

@@ -28,13 +28,6 @@ set -eo pipefail
 # Display commands being run.
 set -x
 
-# Remove expired certificate; otherwise `go mod download` may fail.
-# See https://letsencrypt.org/docs/dst-root-ca-x3-expiration-september-2021/
-# for more context.
-sudo apt-get install -y ca-certificates
-sudo rm -f /usr/share/ca-certificates/mozilla/DST_Root_CA_X3.crt
-sudo update-ca-certificates
-
 cd $(dirname $0)/..
 
 export GOOGLE_APPLICATION_CREDENTIALS="${KOKORO_KEYSTORE_DIR}/72935_cloud-profiler-e2e-service-account-key"