Auto merge of #29963 - mrobinson:run-unit-tests-when-using-try-platform, r=atbrakhi

When using "try-<platform>" trigger unit tests

There is currently no way to trigger unit tests using the bors-servo try
infrastructure. This change makes it so that using try-<platform>
triggers unit tests for that platform. This will be especially useful
when testing changes for Windows before trying to land them.

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<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `___` with appropriate data: -->
- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes do not require tests because they are just GitHub Actions changes.

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0 files changed, 0 insertions, 0 deletions