.github: Add a missing comma to labels-by-language workflow

[cclauss]

Summary

Add a missing comma to the labels-by-language workflow.

• https://github.com/ArduPilot/ardupilot/actions/workflows/labels.yml
• SyntaxError: Unexpected identifier 'pull_number'

Note

One of the strange things about failing GitHub Actions pull_request_trigger jobs is that they will continue to fail until after they are merged. This is because pull_request_trigger jobs run on the master branch, not on the pull request branch.

Classification & Testing (check all that apply and add your own)

• Checked by a human programmer
• Non-functional change
• No-binary change
• Infrastructure change (e.g. unit tests, helper scripts)
• Automated test(s) verify changes (e.g. unit test, autotest)
• Tested manually, description below (e.g. SITL)
• Tested on hardware
• Logs attached
• Logs available on request

Description

[cclauss]

Note

One of the strange things about failing GitHub Actions pull_request_trigger jobs is that they will continue to fail until after they are merged. This is because pull_request_trigger jobs run on the master branch, not on the pull request branch.