updated rustup requirement
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Rustup changed their argparsing, which resulted in `./mach test-unit --nocapture` not working. Servo now requires a higher rustup version to ensure that mach commands work
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- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [ ] These changes fix #__ (github issue number if applicable).
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- [ ] There are tests for these changes OR
- [ ] These changes do not require tests because _____
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Optional backtraces for JS errors and WebGL errors
This adds two new build-time features to enable useful debugging tools when investigating why JS and WebGL content isn't working. They're optional because they're quite heavyweight.
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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 do not require tests because they're optional developer features.
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mach: android install/run: infer adb path from SDK dir
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Infer Android `adb` path from SDK directory in environment variables.
---
<!-- 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 fix#20219 (github issue number if applicable).
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- [ ] There are tests for these changes OR
- [x] These changes do not require tests because it is a build script change
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