[Tests]: updated LLM accuracy references (openvinotoolkit#29135)

Author: AlexKoff88

tests/llm/accuracy_conformance.py

@@ -26,7 +26,7 @@
 
 REFERENCES = {
     "llama": {"INT8": 0.95, "INT4": 0.95},
-    "qwen2": {"INT8": 0.77, "INT4": 0.77},
+    "qwen2": {"INT8": 0.86, "INT4": 0.82},
 }
 ACCURACY_THRESHOLDS = {
     "INT8": 0.05,