Remove num-traits from compositing

[canova]

Thank you for contributing to Servo! Please replace each [ ] by [X] when the step is complete, and replace __ with appropriate data:

• ./mach build -d does not report any errors
• ./mach test-tidy --faster does not report any errors
• These changes fix #11198 (github issue number if applicable).

Either:

• There are tests for these changes OR
• These changes do not require tests

Pull requests that do not address these steps are welcome, but they will require additional verification as part of the review process.

---

This change is

[mbrubeck]

@bors-servo r+

Thanks!

[bors-servo]

📌 Commit 1f5641c has been approved by mbrubeck

[bors-servo]

⌛ Testing commit 1f5641c with merge 8cda146...

[bors-servo]

💔 Test failed - mac-rel-wpt

[highfive]

  ▶ TIMEOUT [expected OK] /html/dom/reflection-embedded.html
  │ 
  │ thread 'http_loader for http://web-platform.test:8000/html/dom/test-valueOf' panicked at 'could not initialize thread_rng: Too many open files (os error 24)', /Users/servo/.cargo/registry/src/github.com-1ecc6299db9ec823/rand-0.3.14/src/lib.rs:873
  │ stack backtrace:
  │    1:        0x10828d5b8 - std::sys::backtrace::tracing::imp::write::h9fb600083204ae7f
  │    2:        0x108293a35 - std::panicking::default_hook::_$u7b$$u7b$closure$u7d$$u7d$::hca543c34f11229ac
  │    3:        0x10829364e - std::panicking::default_hook::hc2c969e7453d080c
  │    4:        0x1079cf042 - util::panicking::initiate_panic_hook::_$u7b$$u7b$closure$u7d$$u7d$::_$u7b$$u7b$closure$u7d$$u7d$::ha2bd86c312dc8d7a
  │    5:        0x10827b2d2 - std::panicking::rust_panic_with_hook::hfe203e3083c2b544
  │    6:        0x108293ff6 - std::panicking::begin_panic::h4889569716505182
  │    7:        0x10827cbc8 - std::panicking::begin_panic_fmt::h484cd47786497f03
  │    8:        0x107ab742f - rand::thread_rng::THREAD_RNG_KEY::__init::h4e1387a2e4a21393
  │    9:        0x107ab726c - rand::thread_rng::he394b446ab605489
  │   10:        0x1079f83d2 - uuid::Uuid::new_v4::hc206acac9c7e580d
  │ thread 'http_loader for http://web-platform.test:8000/html/dom/test-valueOf' panicked at 'could not initialize thread_rng: Too many open files (os error 24)', /Users/servo/.cargo/registry/src/github.com-1ecc6299db9ec823/rand-0.3.14/src/lib.rs:873
  │   11:        0x106b69cdb - net::http_loader::load::h981055a57a1b11f1
  │   12:        0x106b6576b - std::panicking::try::call::h36f7dc6ba106d223
  │   13:        0x1082971bb - __rust_try
  │   14:        0x108297155 - __rust_maybe_catch_panic
  │   15:        0x106b674f4 - _<F as std..boxed..FnBox<A>>::call_box::hdb3e6de044792225
  │   16:        0x108292a58 - std::sys::thread::Thread::new::thread_start::h6f266e069bf4ec2b
  │   17:     0x7fff8c3c2059 - _pthread_body
  │   18:     0x7fff8c3c1fd6 - _pthread_start
  │ stack backtrace:
  │    1:        0x10828d5b8 - std::sys::backtrace::tracing::imp::write::h9fb600083204ae7f
  │    2:        0x108293a35 - std::panicking::default_hook::_$u7b$$u7b$closure$u7d$$u7d$::hca543c34f11229ac
  │    3:        0x10829364e - std::panicking::default_hook::hc2c969e7453d080c
  │    4:        0x1079cf042 - util::panicking::initiate_panic_hook::_$u7b$$u7b$closure$u7d$$u7d$::_$u7b$$u7b$closure$u7d$$u7d$::ha2bd86c312dc8d7a
  │    5:        0x10827b2d2 - std::panicking::rust_panic_with_hook::hfe203e3083c2b544
  │    6:        0x108293ff6 - std::panicking::begin_panic::h4889569716505182
  │    7:        0x10827cbc8 - std::panicking::begin_panic_fmt::h484cd47786497f03
  │    8:        0x107ab742f - rand::thread_rng::THREAD_RNG_KEY::__init::h4e1387a2e4a21393
  │    9:        0x107ab726c - rand::thread_rng::he394b446ab605489
  │   10:        0x1079f83d2 - uuid::Uuid::new_v4::hc206acac9c7e580d
  │   11:        0x106b69cdb - net::http_loader::load::h981055a57a1b11f1
  │   12:        0x106b6576b - std::panicking::try::call::h36f7dc6ba106d223
  │   13:        0x1082971bb - __rust_try
  │   14:        0x108297155 - __rust_maybe_catch_panic
  │   15:        0x106b674f4 - _<F as std..boxed..FnBox<A>>::call_box::hdb3e6de044792225
  │   16:        0x108292a58 - std::sys::thread::Thread::new::thread_start::h6f266e069bf4ec2b
  │   17:     0x7fff8c3c2059 - _pthread_body
  └   18:     0x7fff8c3c1fd6 - _pthread_start

[mbrubeck]

@bors-servo retry

• #11100

[bors-servo]

⌛ Testing commit 1f5641c with merge fe4061e...

[bors-servo]

☀️ Test successful - android, arm32, arm64, linux-dev, linux-rel, mac-dev-unit, mac-rel-css, mac-rel-wpt, windows