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* [x] I have searched the issue tracker for an issue that matches the one I want to file, without success.

### Issue Details

* **Electron Version:**
  * 9.3.4
* **Operating System:**
  * Arch Linux
* **Last Known Working Electron version:**
  * 9.3.3

### Expected Behavior
```
❱ echo lang: $LANG lc_all: $LC_ALL
lang: en_US.UTF-8 lc_all:
❱ electron9 -i                    
> process.env.LC_ALL
undefined
```

### Actual Behavior
```
❱ echo lang: $LANG lc_all: $LC_ALL
lang: en_US.UTF-8 lc_all:
❱ electron9 -i                    
> process.env.LC_ALL
'en_US'
```

`en_US` is not a valid locale—it has to be `en_US.UTF-8`, however, Electron overrides this, even if `--lang=en_US.UTF-8` is passed or `LC_ALL` is set correctly when invoking Electron. With this invalid value, many C programs fail to run.

### To Reproduce
Run the above commands.

### Additional Information
Problem introduced in  #26242
shell/browser/electron_browser_main_parts.cc
#include "ui/base/cursor/cursor_loader_win.h"
#include "ui/base/l10n/l10n_util_win.h"
#include "ui/display/win/dpi.h"
#include "ui/gfx/system_fonts_win.h"
#include "ui/strings/grit/app_locale_settings.h"
#endif
#if defined(OS_MAC)
#include "shell/browser/ui/cocoa/views_delegate_mac.h"
#else
#include "shell/browser/ui/views/electron_views_delegate.h"
#endif
#if defined(OS_LINUX)
#include "device/bluetooth/bluetooth_adapter_factory.h"
#include "device/bluetooth/dbus/dbus_bluez_manager_wrapper_linux.h"
#endif
#if BUILDFLAG(ENABLE_ELECTRON_EXTENSIONS)
#include "components/keyed_service/content/browser_context_dependency_manager.h"
#include "extensions/browser/browser_context_keyed_service_factories.h"
#include "extensions/common/extension_api.h"
#include "shell/browser/extensions/electron_browser_context_keyed_service_factories.h"
#include "shell/browser/extensions/electron_extensions_browser_client.h"
#include "shell/common/extensions/electron_extensions_client.h"
#endif  
#if BUILDFLAG(ENABLE_BUILTIN_SPELLCHECKER)
#include "chrome/browser/spellchecker/spellcheck_factory.h"  
#endif
namespace electron {
namespace {
template <typename T>
void Erase(T* container, typename T::iterator iter) {