[Fix](CI) Avoid AI Review opinion line breaks (#63672)

fix format error like
https://github.com/apache/doris/pull/63615#pullrequestreview-4361582475

.github/workflows/opencode-review-runner.yml

@@ -177,6 +177,7 @@ jobs:
           ## Final response format
           - After completing the review, you MUST provide a final summary opinion based on the rules defined in AGENTS.md and the code-review skill. The summary must include conclusions for each applicable critical checkpoint.
           - If the overall quality of PR is good and there are no critical blocking issues (even if there are some tolerable minor issues), submit an opinion on approval using: gh pr review PLACEHOLDER_PR_NUMBER --comment --body "<summary>"
+              - Note that when submitting review comments in this way, the content will not be escaped, so you need to input multi-line text with line breaks directly, rather than using `\n`.
           - If issues found, submit a review with inline comments plus a comprehensive summary body. Use GitHub Reviews API to ensure comments are inline:
               - Inline comment bodies may include GitHub suggested changes blocks when you can propose a precise patch.
               - Prefer suggested changes for small, self-contained fixes (for example typos, trivial refactors, or narrowly scoped code corrections).