Enable llama3 for Duo Chat

ee/lib/gitlab/ai/feature_settings/feature_metadata.yml

@@ -35,6 +35,7 @@ duo_chat:
     - mixtral
     - claude_3
     - gpt
+    - llama3
 duo_chat_explain_code:
   title: Explain Code
   release_state: BETA
@@ -66,6 +67,7 @@ duo_chat_refactor_code:
     - claude_3
     - gpt
     - codestral
+    - llama3
 duo_chat_fix_code:
   title: Fix Code
   release_state: BETA
@@ -76,6 +78,7 @@ duo_chat_fix_code:
     - claude_3
     - gpt
     - codestral
+    - llama3
 duo_chat_troubleshoot_job:
   title: Troubleshoot Job
   release_state: BETA
@@ -85,3 +88,4 @@ duo_chat_troubleshoot_job:
     - mixtral
     - claude_3
     - gpt
+    - llama3