Update x11-dl to pickup the fix for x11 startup crash (recurrence of #21530)

[vbkaisetsu]

This branch updates x11-dl to 2.18.5 to get erlepereira/x11-rs#99

% ./mach run --release https://duckduckgo.com                             
attempted to leave type `std::mem::ManuallyDrop<xlib_xcb::Xlib_xcb>` uninitialized, which is invalid (thread main, at /rustc/45ebd5808afd3df7ba842797c0fcd4447ddf30fb/src/libcore/mem/mod.rs:536)     
stack backtrace:                                                                                   
   0: servo::backtrace::print                   
   1: servo::main::{{closure}}        
   2: std::panicking::rust_panic_with_hook
             at src/libstd/panicking.rs:513                                                        
   3: rust_begin_unwind                       
             at src/libstd/panicking.rs:417                                                        
   4: core::panicking::panic_fmt
             at src/libcore/panicking.rs:111                                                       
   5: core::panicking::panic                     
             at src/libcore/panicking.rs:54 
   6: x11_dl::xlib_xcb::Xlib_xcb::open                                                                                                                                                                
   7: winit::platform::platform::x11::xdisplay::XConnection::new                                   
   8: std::sync::once::Once::call_once::{{closure}}                 
   9: std::sync::once::Once::call_inner          
             at src/libstd/sync/once.rs:416
  10: winit::platform::platform::EventsLoop::new_x11
  11: winit::platform::platform::EventsLoop::new
  12: winit::EventsLoop::new
  13: servo::events_loop::EventsLoop::new
  14: servo::app::App::run
  15: servo::main
  16: std::rt::lang_start::{{closure}}
  17: std::rt::lang_start_internal::{{closure}}
             at src/libstd/rt.rs:52
      std::panicking::try::do_call
             at src/libstd/panicking.rs:329
      std::panicking::try::do_try
             at src/libstd/panicking.rs:285
      std::panicking::try
             at src/libstd/panicking.rs:274
      std::panic::catch_unwind
             at src/libstd/panic.rs:394
      std::rt::lang_start_internal
             at src/libstd/rt.rs:51
  18: main
  19: __libc_start_main
  20: _start
Servo exited with return value 101

This patch is created by cargo update -p x11-dl.

---

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

• There are tests for these changes OR
• These changes do not require tests because it fixes a startup crash

[highfive]

Thanks for the pull request, and welcome! The Servo team is excited to review your changes, and you should hear from @nox (or someone else) soon.

[jdm]

@bors-servo r+

[bors-servo]

📌 Commit 9f892eb has been approved by jdm

[bors-servo]

⌛ Testing commit 9f892eb with merge 2b0a48f...

[bors-servo]

☀️ Test successful - status-taskcluster
Approved by: jdm
Pushing 2b0a48f to master...