Fixed typo (#26260)

packages/flutter/lib/src/material/typography.dart

@@ -142,7 +142,7 @@ class Typography extends Diagnosticable {
   ///
   /// This [TextTheme] provides color but not geometry (font size, weight, etc).
   /// A text theme's geometry depends on the locale. To look up a localized
-  /// [TextTheme], use the the overall [Theme], for example:
+  /// [TextTheme], use the overall [Theme], for example:
   /// `Theme.of(context).textTheme`.
   ///
   /// The [englishLike], [dense], and [tall] text theme's provide locale-specific