build(deps): bump openai from 2.6.1 to 2.8.1 (#100)

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

requirements.txt

@@ -2,6 +2,6 @@ slack-bolt==1.27.0
 pytest
 ruff
 slack-cli-hooks==0.2.0
-openai==2.6.1
+openai==2.8.1
 anthropic==0.75.0
 google-cloud-aiplatform==1.128.0