chore: llm chain update with system_prompt support (#15)

Author: chr-hertel

Diff for: composer.json

@@ -9,7 +9,7 @@
         "ext-iconv": "*",
         "codewithkyrian/chromadb-php": "^0.3.0",
         "league/commonmark": "^2.6",
-        "php-llm/llm-chain-bundle": "^0.12",
+        "php-llm/llm-chain-bundle": "^0.13",
         "phpdocumentor/reflection-docblock": "^5.5",
         "phpstan/phpdoc-parser": "^1.33",
         "runtime/frankenphp-symfony": "^0.2.0",