Replace GPT and Claude models to latest, better and cheaper models (#118)

* Updated GPT and Claude models to latest, better and cheaper models

* updated more files to use GPT-5 and Sonnet/Haiku 4.5 because theu are the latest, cheaper and better models

plugins/llm-application-dev/skills/prompt-engineering-patterns/references/chain-of-thought.md

@@ -65,7 +65,7 @@ def self_consistency_cot(query, n=5, temperature=0.7):
     responses = []
     for _ in range(n):
         response = openai.ChatCompletion.create(
-            model="gpt-4",
+            model="gpt-5",
             messages=[{"role": "user", "content": prompt}],
             temperature=temperature
         )