MT#62936 Update memtest

1. Add new screenshot with memtest v7 which is in trixie.
2. Use new screenshot for trixie builds.
3. Check the RC. According to the help page of screenshot-compare RC
higher then 100 means 'high difference'.
4. Bump REFRESHED_AT ro regenerate docker image.

Change-Id: I99fe27c146aefba3778d03b7d19c1c0bce52a635
(cherry picked from commit b8e842398a)
(cherry picked from commit 21623e37bc)

build_iso.sh

@@ -50,10 +50,14 @@ case "${GRML_ISO}" in
     MEMTEST_SCREENSHOT="/code/t/screenshots/01-memtest-v5.jpg"
     echo "*** NOTE: identified Grml ISO ${GRML_ISO}, assuming we have memtest v5"
     ;;
-  *)
+  grml*bookworm*)
     MEMTEST_SCREENSHOT="/code/t/screenshots/01-memtest-v6.jpg"
     echo "*** NOTE: identified Grml ISO ${GRML_ISO}, assuming we have memtest v6"
     ;;
+  *)
+    MEMTEST_SCREENSHOT="/code/t/screenshots/01-memtest-v7.jpg"
+    echo "*** NOTE: identified Grml ISO ${GRML_ISO}, assuming we have memtest v7"
+    ;;
 esac
 
 SCRIPT="$(readlink -f "$0")"

t/Dockerfile

@@ -5,7 +5,7 @@ FROM docker.mgm.sipwise.com/sipwise-trixie:latest
 # is updated with the current date. It will force refresh of all
 # of the base images and things like `apt-get update` won't be using
 # old cached versions when the Dockerfile is built.
-ENV REFRESHED_AT=2025-07-21
+ENV REFRESHED_AT=2025-07-22
 
 RUN apt-get update && apt-get install --assume-yes git make gcc dpkg-dev
 

t/iso-tester

@@ -92,7 +92,9 @@ fi
 mkdir -p reports
 if [ -n "${SCREENSHOT_COMPARE:-}" ] ; then
   echo "Comparing ${SCREENSHOT} against ${SCREENSHOT_COMPARE}"
-  if ./screenshot-compare "${SCREENSHOT}" "${SCREENSHOT_COMPARE}" ; then
+  RC=0
+  ./screenshot-compare "${SCREENSHOT}" "${SCREENSHOT_COMPARE}" || RC=$?
+  if [[ "${RC}" -lt 100 ]] ; then
     echo "Looks like ${SCREENSHOT} and ${SCREENSHOT_COMPARE} are looking similar enough."
     echo "1..0" > ./reports/screenshot.tap
   else