Abort execution on non-0 exit status from "after" scripts

Failures in "after" scripts do not currently result in bootstrap
failures since "find" ignores the exit code of commands that it
executes.

There are no simple options in "find" to both propagate non-0 exit
statuses of executed commands and also abort its command execution
sequence in such an event. As such, use "find" only for listing
script names and otherwise use a simple loop to execute them.

While at it, execute scripts in numerical order according to their
basename. This gives consumers control over the execution order of
their scripts. For example, 50-sign.sh will be executed before
51-upload.sh.

steps/improve/after.sh

@@ -1,6 +1,7 @@
 #!/bin/sh
 #
 # SPDX-FileCopyrightText: 2024 Gábor Stefanik <[email protected]>
+# SPDX-FileCopyrightText: 2025 Dor Askayo <[email protected]>
 #
 # SPDX-License-Identifier: GPL-3.0-or-later
 #
@@ -10,7 +11,10 @@
 . /steps/env
 
 if [ -d /steps/after ]; then
-    find /steps/after -maxdepth 1 -name '*.sh' -exec bash {} \;
+    after_scripts=$(find /steps/after -maxdepth 1 -type f -name '*.sh' -printf '%f\t%p\n' | sort -k1 -n | cut -f2)
+    for script in $after_scripts; do
+        bash "$script"
+    done
 fi
 
 if [ "${INTERACTIVE}" = True ]; then