fly installer update.

Signed-off-by: Volkan Özçelik <volkan.ozcelik@broadcom.com>

hack/setup-fly.sh

@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 
-# Copyright 2020-2025 the Pinniped contributors. All Rights Reserved.
+# Copyright 2020-2026 the Pinniped contributors. All Rights Reserved.
 # SPDX-License-Identifier: Apache-2.0
 
 set -euo pipefail
@@ -10,9 +10,15 @@ script_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
 # Define some env vars
 source "$script_dir/fly-helpers.sh"
 
-# Install the fly cli if needed
-if [[ ! -f "$FLY_CLI" ]]; then
-  curl -fL "$CONCOURSE_URL/api/v1/cli?arch=amd64&platform=darwin" -o "$FLY_CLI"
+# Install the fly cli if missing or unable to run on this platform.
+if [[ ! -x "$FLY_CLI" ]] || ! "$FLY_CLI" --version >/dev/null 2>&1; then
+  fly_arch="$(uname -m)"
+  case "$fly_arch" in
+    x86_64) fly_arch="amd64" ;;
+    aarch64) fly_arch="arm64" ;;
+  esac
+  fly_platform="$(uname -s | tr '[:upper:]' '[:lower:]')"
+  curl -fL "$CONCOURSE_URL/api/v1/cli?arch=${fly_arch}&platform=${fly_platform}" -o "$FLY_CLI"
   chmod 755 "$FLY_CLI"
 fi