Add GPT-5.5 and GPT-5.4 mini model card links to model comparison table (#61118)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: sunbrye <56200261+sunbrye@users.noreply.github.com>
Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

Author: 3 people

data/tables/copilot/model-comparison.yml

@@ -40,12 +40,12 @@
 - name: GPT-5.4 mini
   task_area: Agentic software development
   excels_at: Codebase exploration and is especially effective when using grep-style tools
-  further_reading: 'Not available'
+  further_reading: '[GPT-5.4 mini model card](https://deploymentsafety.openai.com/gpt-5-4-thinking/gpt-5-4-thinking.pdf)'
 
 - name: GPT-5.5
   task_area: Deep reasoning and debugging
   excels_at: Multi-step problem solving and architecture-level code analysis
-  further_reading: 'Not available'
+  further_reading: '[GPT-5.5 model card](https://deploymentsafety.openai.com/gpt-5-5/gpt-5-5.pdf)'
 
 # Anthropic
 - name: Claude Haiku 4.5