Remove materialTypography val from ElementTheme.

We should only use `typography`.

libraries/compound/src/main/kotlin/io/element/android/compound/theme/ElementTheme.kt

@@ -62,14 +62,6 @@ object ElementTheme {
      */
     val typography: TypographyTokens = TypographyTokens
 
-    /**
-     * Material 3 [Typography] tokens. In Figma, these have the `M3 Typography/` prefix.
-     */
-    val materialTypography: Typography
-        @Composable
-        @ReadOnlyComposable
-        get() = MaterialTheme.typography
-
     /**
      * Returns whether the theme version used is the light or the dark one.
      */