.editorconfig: Update CMake style 

Trigraphs support is generally disabled by default, but some compilers
(e.g. GCC) may still warn when one hypothetical trigraph is encountered.

For example, one of these warnings was introduced as part of #14067:

```
.../Source/Core/DolphinQt/MainWindow.cpp:1433:77: warning: trigraph ??) ignored, use -trigraphs to enable [-Wtrigraphs]
 1433 |       this, tr("Select a File"), dialog_path, tr("All Save States (*.sav *.s??);; All Files (*)"));
      |
.../Source/Core/DolphinQt/MainWindow.cpp:1445:77: warning: trigraph ??) ignored, use -trigraphs to enable [-Wtrigraphs]
 1445 |       this, tr("Select a File"), dialog_path, tr("All Save States (*.sav *.s??);; All Files (*)"));
      |
```

The warning is generally not interesting and has been disabled now.

This warning unhelpfully triggers for the `[x = std::move(x)]` pattern
which is used quite a few times in Dolphin.

For parity with GCC.

This reverts commit fb265b610de08df5509e56beeb3dbff68f7d4396.

The optimization in that commit is safe when the executor thread is
writing and the GUI thread is reading, but I had failed to take into
account that it's unsafe when the GUI thread is writing and the executor
thread is reading. (The native UpdateAdditionalMetadata function loops
through m_cached_files, which is unsafe if another thread is adding
elements to m_cached_files simultaneously.)

Losing out on this optimization isn't too bad, because
719930bb390ed0020b99a7942289d83218e99d69 makes it very unlikely that
both threads will want the lock at the same time.