feature #6627 Change the default theme to auto (javiereguiluz)

This PR was merged into the 4.x branch.

Discussion
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Change the default theme to auto

As mentioned in #6433 (comment)

#SymfonyHackday

Commits
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bc893f9 Change the default theme to auto

src/Dto/DashboardDto.php

@@ -20,7 +20,7 @@ final class DashboardDto
     private bool $signedUrls = false;
     private bool $absoluteUrls = true;
     private bool $enableDarkMode = true;
-    private string $defaultColorScheme = ColorScheme::LIGHT;
+    private string $defaultColorScheme = ColorScheme::AUTO;
     /** @var LocaleDto[] */
     private array $locales = [];