build: remove legacy integration test runner (#35985)

* integration tests target definitions in integration/BUILD.bazel updated to use a single dict
* payload tracking for integration tests updated to work under Bazel
* legacy integration_test CI job removed
* integration/run_tests.sh script no longer used in CI so it has been updated for running integration tests locally in the legacy way

PR Close #35985

scripts/ci/track-payload-size.sh

@@ -0,0 +1,18 @@
+#!/usr/bin/env bash
+
+set -eu -o pipefail
+
+# Source optional CI environment variables which are sandboxed out
+# of the environment when running integration tests under Bazel
+readonly bazelVarEnv="/tmp/bazel-ci-env.sh"
+if [[ -f "$bazelVarEnv" ]]; then
+  source $bazelVarEnv
+fi
+
+# If running locally, at a minimum set PROJECT_ROOT
+if [[ -z "${PROJECT_ROOT:-}" ]]; then
+  PROJECT_ROOT=$(cd $(dirname $0)/../..; pwd)
+fi
+
+source ${PROJECT_ROOT}/scripts/ci/payload-size.sh
+trackPayloadSize "$@"