ci: remove hardcoded cagent version from agent writer workflow

Signed-off-by: David Karlsson <35727626+dvdksn@users.noreply.github.com>

Author: dvdksn

.github/workflows/agent-writer.yml

@@ -1,4 +1,4 @@
-name: Agent
+name: Agent writer
 
 on:
   issues:
@@ -28,7 +28,6 @@ jobs:
         uses: docker/cagent-action@latest
         timeout-minutes: 15
         with:
-          cagent-version: v1.22.0
           agent: ./tech_writer.yml
           yolo: true
           prompt: |