fix(pkg-cache): no | while read pipelines under pipefail

Shell-Checks' structural scan (scripts/tests/lsphp-info-probe.test.sh)
flagged two `cmd | while read` loops in pkg-cache-repos.sh restore.
Read the lists with mapfile from a process substitution instead, so
there is no pipeline. The test now passes locally (36/0), shellcheck is
clean, and the restore tests (new cache-referencing file removed,
leftover reference -> FATAL) behave as before.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

scripts/pkg-cache-repos.sh

@@ -83,13 +83,17 @@ created() { printf '%s\n' "$1" >> "$STATE/created"; }
 if [ "$MODE" = restore ]; then
     [ -d "$STATE" ] || exit 0
     host=$(cat "$STATE/host")
-    (cd "$STATE/orig" && find . -type f) | while read -r rel; do
+    # mapfile from a process substitution, not `cmd | while read`: no pipeline,
+    # so nothing for pipefail to misreport (scripts/tests/lsphp-info-probe.test.sh).
+    mapfile -t saved < <(cd "$STATE/orig" && find . -type f)
+    for rel in "${saved[@]}"; do
         cat "$STATE/orig/$rel" > "/${rel#./}"
     done
     while read -r f; do [ -n "$f" ] && rm -f -- "$f"; done < "$STATE/created"
     # A repo/apt file that appeared during this RUN and still names the cache
     # (e.g. written by a package from the rewritten repos) is removed too.
-    repo_files | while read -r f; do
+    mapfile -t current < <(repo_files)
+    for f in "${current[@]}"; do
         if ! grep -qxF -- "$f" "$STATE/manifest" && grep -qF -- "$host" "$f"; then
             echo "pkg-cache-repos: removing new file that references the cache: $f"
             rm -f -- "$f"