Fix random kills during pre-commit image building (#11535)

Seems like the trap with several steps and || true does not really
work the way I wanted and when kill is run but the process is
already gone, we had error in the script.

Looks like this approach with sub-process kill will do it.

scripts/ci/libraries/_build_images.sh

@@ -519,8 +519,8 @@ function build_images::build_ci_image() {
         " >"${DETECTED_TERMINAL}"
         spinner::spin "${OUTPUT_LOG}" &
         SPIN_PID=$!
-        # shellcheck disable=SC2064
-        traps::add_trap "kill ${SPIN_PID} || true" INT TERM HUP EXIT
+        # shellcheck disable=SC2064,SC2016
+        traps::add_trap '$(kill '${SPIN_PID}' || true)' EXIT HUP INT TERM
     fi
     push_pull_remove_images::pull_ci_images_if_needed
     if [[ "${DOCKER_CACHE}" == "disabled" ]]; then
@@ -557,8 +557,8 @@ function build_images::build_ci_image() {
         " >"${DETECTED_TERMINAL}"
         spinner::spin "${OUTPUT_LOG}" &
         SPIN_PID=$!
-        # shellcheck disable=SC2064
-        traps::add_trap "kill ${SPIN_PID} || true" EXIT HUP INT TERM
+        # shellcheck disable=SC2064,SC2016
+        traps::add_trap '$(kill '${SPIN_PID}' || true)' EXIT HUP INT TERM
     fi
     if [[ -n ${DETECTED_TERMINAL=} ]]; then
         echo -n "