Fix macOS compatibility of update-lexbor.sh

[Tim: Extracted this as a new commit from phpGH-22699]

Author: kocsismate

ext/dom/lexbor/patches/update-lexbor.sh

@@ -19,7 +19,10 @@ git clone "$LEXBOR_REPO" "$LEXBOR_TMP_DIR"
 (cd "$LEXBOR_TMP_DIR" && git checkout "$LEXBOR_REF")
 
 # Apply patches
-mapfile -t patches < <(ls "$PATCHES_DIR"/*.patch)
+patches=()
+for f in "$PATCHES_DIR"/*.patch; do
+    [ -e "$f" ] && patches+=("$f")
+done
 cd "$LEXBOR_TMP_DIR"
 for patch in "${patches[@]}"; do
     if ! git am -3 "$patch"; then