refactor(select): Remove fullwidth property

PiperOrigin-RevId: 317731796

packages/mdc-select/README.md

@@ -225,11 +225,6 @@ same.
 </div>
 ```
 
-### Fullwidth Select
-
-The Select Fullwidth variant takes up the entirety of the width of its parent container. To use this variant, place the
-`mdc-select--fullwidth` modifier class on the root element.
-
 ### Additional Information
 
 #### Select with pre-selected option

packages/mdc-select/_mixins.scss

@@ -165,10 +165,6 @@
 
   @include text_($query: $query);
 
-  .mdc-select--fullwidth {
-    @include fullwidth_($query: $query);
-  }
-
   .mdc-select--outlined {
     @include outlined_($query: $query);
   }
@@ -839,17 +835,6 @@
   }
 }
 
-///
-/// Sets the select to take the full width of its parent container.
-///
-@mixin fullwidth_($query: feature-targeting-functions.all()) {
-  $feat-structure: feature-targeting-functions.create-target($query, structure);
-
-  @include feature-targeting-mixins.targets($feat-structure) {
-    width: 100%;
-  }
-}
-
 /// Adds horizontal padding to the selected text
 ///
 /// @param {Number} $left - left side padding