Quieter output during asset compilation (#30565)

The "Still waiting ....." message was emitted every second, which can be
quite noisy even on moderate machines. This reduces the message to once
every 5 seconds.

Author: uranusjr

Dockerfile.ci

@@ -628,7 +628,9 @@ function wait_for_asset_compilation() {
         echo
         local counter=0
         while [[ -f "${AIRFLOW_SOURCES}/.build/www/.asset_compile.lock" ]]; do
-            echo "${COLOR_BLUE}Still waiting .....${COLOR_RESET}"
+            if (( counter % 5 == 2 )); then
+                echo "${COLOR_BLUE}Still waiting .....${COLOR_RESET}"
+            fi
             sleep 1
             ((counter=counter+1))
             if [[ ${counter} == "30" ]]; then

scripts/docker/entrypoint_ci.sh

@@ -52,7 +52,9 @@ function wait_for_asset_compilation() {
         echo
         local counter=0
         while [[ -f "${AIRFLOW_SOURCES}/.build/www/.asset_compile.lock" ]]; do
-            echo "${COLOR_BLUE}Still waiting .....${COLOR_RESET}"
+            if (( counter % 5 == 2 )); then
+                echo "${COLOR_BLUE}Still waiting .....${COLOR_RESET}"
+            fi
             sleep 1
             ((counter=counter+1))
             if [[ ${counter} == "30" ]]; then