Fix claude model name (#4798)

Author: marcoacierno

.github/workflows/claude.yml

@@ -83,7 +83,7 @@ jobs:
           claude_code_oauth_token: ${{ secrets.CLAUDE_OAUTH_TOKEN }}
           assignee_trigger: "pythonitaliabot2"
           claude_args: |
-            --model claude-opus-5-0
+            --model claude-opus-5
             --effort xhigh
             --append-system-prompt "CI MODE. You are running in GitHub Actions against a plain checkout, not a developer laptop. Ignore the 'run everything inside docker exec pycon-backend-1' instructions in AGENTS.md: there is no Docker container here. Backend dependencies are already installed with 'uv sync' in ./backend, and Postgres and Redis are running with DATABASE_URL and CELERY_* already exported. Verify backend changes with: cd backend && uv run pytest <paths> -x -q (add '-n auto' for the full suite), uv run mypy ., uv tool run ruff@0.12.5 check, uv tool run ruff@0.12.5 format --check. Always prefix Python tooling with 'uv run' or 'uv tool run' - bare python, pytest, mypy and ruff are not on PATH and are not permitted. Run the tests covering your change before you report back, and quote the real output."
             --allowedTools "Edit,Write,Bash(cd:*),Bash(git:*),Bash(uv:*),Bash(pip:*),Bash(gh pr view:*),Bash(gh pr diff:*),Bash(gh pr list:*),Bash(gh pr comment:*),Bash(gh issue view:*),Bash(gh issue list:*),Bash(gh search:*)"