Revert "5.5: Update ubuntu base image for esp-env-v5.5 to 24.04"

This reverts commit 60ed896b08.

.gitlab/ci/common.yml

@@ -55,7 +55,7 @@ variables:
   CHECKOUT_REF_SCRIPT: "$CI_PROJECT_DIR/tools/ci/checkout_project_ref.py"
 
   # Docker images
-  ESP_ENV_IMAGE: "${CI_DOCKER_REGISTRY}/esp-env-v5.5:3"
+  ESP_ENV_IMAGE: "${CI_DOCKER_REGISTRY}/esp-env-v5.5:2"
   ESP_IDF_DOC_ENV_IMAGE: "${CI_DOCKER_REGISTRY}/esp-idf-doc-env-v5.5:2-1"
   TARGET_TEST_ENV_IMAGE: "${CI_DOCKER_REGISTRY}/target-test-env-v5.5:2"
   SONARQUBE_SCANNER_IMAGE: "${CI_DOCKER_REGISTRY}/sonarqube-scanner:5"

.gitlab/ci/host-test.yml

@@ -239,7 +239,6 @@ test_mqtt_on_host:
 
 test_transport_on_host:
   extends: .host_test_template
-  allow_failure: true # IDFCI-2781 [v5.5, v5.4] test_transport_on_host fails on ubuntu 24.04
   script:
     - cd ${IDF_PATH}/components/tcp_transport/host_test
     - idf.py build