Make Windows arm64 easy
* Add a ServoApp project configuration
* Add a `--win-arm64` build flag (now `python mach build -r --win-arm64 --uwp`)
* Automatically set up GStreamer LIB environment
* Yell if the cross-compilation environment isn't set up correctly
* Automatically find the Visual C++ installation for DLL packaging, rather than relying on an environment variable
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- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix#23793 and fix#23795
- [x] There are tests for these changes
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Filter intermittent wdspec tests failures
<!-- Please describe your changes on the following line: -->
With this change, the intermittent failures for wdspec tests will be filtered and reported.
---
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- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
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Build simpleservo on Windows
The mozangle change means that we don't rebuild mozangle (and transitively script) because the requested features are different when building libsimpleservo.
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Reintroduce parallelism in the bluetooth tests
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With https://github.com/web-platform-tests/wpt/pull/16819 in place, https://github.com/servo/servo/issues/22619 should be fixed, so the changes introduced by https://github.com/servo/servo/pull/22662 can be reverted.
---
<!-- 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
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Fix nightly WPT sync job
These changes were tested by triggering the daily hook with a branch that included them, and they caused #23433 to be opened successfully.
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