Inline code in commit titles renders incorrectly when code starts with a period

#### Environment details

- OS: GitHub Actions (ubuntu-latest)
- Node.js version: N/A (using latest `googleapis/release-please-action`)
- npm version: N/A
- `release-please` version: latest (via `googleapis/release-please-action`)

#### Steps to reproduce

1. Create and merge a PR with a commit title containing inline code that starts with a period, e.g.:
```
feat(cli): support `.agents/skills` dir alias
```
2. Wait for release-please to generate a release PR
3. Observe the generated PR body/changelog entry

**Expected result:**

The inline code renders correctly:

> **cli:** support `.agents/skills` dir alias

**Actual result:**

The markdown appears malformed. The period inside the backticks causes the inline code to break:

> **cli:** support .`agents/skills` dir alias

Note the period has moved outside the backticks in the rendered output.

#### Additional context

- Example release PR with broken formatting: https://github.com/langchain-ai/deepagents/pull/1062
- Original commit PR (title renders correctly): https://github.com/langchain-ai/deepagents/pull/1059

Potentially related issues:
- #2366 / #2367 (HTML tags escaped inside code blocks)
- #2020 (commits with fenced code blocks ignored)