chore(deps): update dependency chenxiaolong/custota to v5.6 (#7)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

rooted-ota.sh

@@ -52,7 +52,7 @@ OTA_BASE_URL="https://releases.grapheneos.org"
 
 AVB_ROOT_VERSION=3.12.0
 
-CUSTOTA_VERSION=5.5
+CUSTOTA_VERSION=5.6
 
 CHENXIAOLONG_PK='ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIDOe6/tBnO7xZhAWXRj3ApUYgn+XZ0wnQiXM8B7tPgv4'