Add 'try-**' branch to CI PR triggers

[seanbudd]

Link to issue number:

None

Summary of the issue:

We occasionally want to run feature branches, that get PR builds when a PR is open against them

Description of user facing changes:

none

Description of developer facing changes:

none

Description of development approach:

Add try- branches to the list of branches that get PR builds

Testing strategy:

N/A

Known issues with pull request:

none

Code Review Checklist:

• Documentation:
  • Change log entry
  • User Documentation
  • Developer / Technical Documentation
  • Context sensitive help for GUI changes
• Testing:
  • Unit tests
  • System (end to end) tests
  • Manual testing
• UX of all users considered:
  • Speech
  • Braille
  • Low Vision
  • Different web browsers
  • Localization in other languages / culture than English
• API is compatible with existing add-ons.
• Security precautions taken.