fix(packaging): skip Linux GPU libraries on Darwin (#12466)

Return before initializing Linux library helpers on macOS. The system
Bash lacks associative arrays, and Metal uses system frameworks.

Assisted-by: Codex:gpt-6

Co-authored-by: localai-org-maint-bot <306269227+localai-org-maint-bot@users.noreply.github.com>

scripts/build/package-gpu-libs-darwin_test.sh

@@ -0,0 +1,19 @@
+#!/bin/bash
+# Darwin uses system GPU frameworks and ships Bash 3.2 without associative arrays.
+set -euo pipefail
+SCRIPT="$(dirname "$(realpath "$0")")/package-gpu-libs.sh"
+WORK=$(mktemp -d)
+trap 'rm -rf "$WORK"' EXIT
+uname() { echo Darwin; }
+declare() {
+    if [[ "${1:-}" == -A ]]; then
+        echo 'Bash 3.2 does not support declare -A' >&2
+        return 2
+    fi
+    builtin declare "$@"
+}
+export BUILD_TYPE=metal
+source "$SCRIPT" "$WORK/lib"
+package_gpu_libs
+test -z "$(find "$WORK" -type f -print)"
+echo 'PASS: Darwin does not load the Linux GPU packager'

scripts/build/package-gpu-libs.sh

@@ -15,6 +15,16 @@
 
 set -e
 
+# macOS uses system GPU frameworks; this packager handles Linux ELF libraries.
+# Return before Bash 3.2 encounters the associative arrays used below.
+if [[ "$(uname -s)" == Darwin ]]; then
+    package_gpu_libs() {
+        echo "Detected Darwin; no Linux GPU libraries to package"
+    }
+    export -f package_gpu_libs
+    return 0 2>/dev/null || exit 0
+fi
+
 TARGET_LIB_DIR="${1:-./lib}"
 
 # Create target directory if it doesn't exist