chore: add if condition to pr-triage

[dylan-apex]

Currently when this workflow runs, it does all of the setup and then in the triaging script it checks if the PR has already been triaged, leading to ~45 seconds of wasted runtime. We can add a condition so that the workflow only runs when the PR does not have the bot triaged label

Leaving the instructions that reference the label since it also includes the google-contributor one

[gemini-code-assist]

Note

Gemini is unable to generate a summary for this pull request due to the file types involved not being currently supported.

[adk-bot]

Response from ADK Triaging Agent

Hello @dylan-apex, thank you for creating this PR!

Could you please include a testing plan section in your PR to describe how you tested these changes? This will help reviewers to review your PR more efficiently.

You can find more information in our contribution guidelines. Thanks!

[dylan-apex]

@hangfei You're probably the best reviewer for this PR

[hangfei]

@dylan-apex thanks! Is there a way for you to test this change?

[dylan-apex]

@hangfei tested on my repo. added bot triaged tag and the workflow was skipped on edits.

[hangfei]

@xuanyang15 Could you help review this? Thanks.

[xuanyang15]

Closing this PR because the change has been added in 78eea1a.