chore(deps-dev): bump com.openai:openai-java from 4.22.0 to 4.26.0

Bumps [com.openai:openai-java](https://github.com/openai/openai-java) from 4.22.0 to 4.26.0.
- [Release notes](https://github.com/openai/openai-java/releases)
- [Changelog](https://github.com/openai/openai-java/blob/main/CHANGELOG.md)
- [Commits](openai/openai-java@v4.22.0...v4.26.0)

---
updated-dependencies:
- dependency-name: com.openai:openai-java
  dependency-version: 4.26.0
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

agentscope-dependencies-bom/pom.xml

@@ -77,7 +77,7 @@
         <google-genai.version>1.38.0</google-genai.version>
         <dashscope-sdk-java.version>2.22.9</dashscope-sdk-java.version>
         <bailian.version>2.8.1</bailian.version>
-        <openai-java.version>4.22.0</openai-java.version>
+        <openai-java.version>4.26.0</openai-java.version>
         <anthropic.version>2.14.0</anthropic.version>
         <mcp.version>0.17.0</mcp.version>
         <slf4j.version>2.0.17</slf4j.version>