Change sequential thinking icons

Author: colinmcneil

prompts/catalog.yaml

@@ -559,7 +559,7 @@ registry:
   sequentialthinking:
     description: provides a tool for dynamic and reflective problem-solving through a structured thinking process
     ref: github:docker/labs-ai-tools-for-devs?ref=main&path=prompts/examples/sequentialthinking.md
-    icon: https://2.gravatar.com/userimage/39790510/4918b92358fde20da56c0ec8e5ac7a23?size=256
+    icon: https://d3t3ozftmdmh3i.cloudfront.net/production/podcast_uploaded_nologo/2454513/2454513-1570719639731-bfdf3620a4e0d.jpg
     tools:
       - type: function
         function: