Remove max width from buttons with custom width set

PR WordPress#23168 overhauls alignment controls on the Buttons container and
allows for full width. For a Button inside a very large container,
in order to be set correctly to 100% it must be able to exceed any
configured max-width.

This commit does not remove the max-width for any button that does
NOT have a custom width percentage selected. This is so that
default buttons continue to be sized as they normally would.

packages/block-library/src/button/edit.js

@@ -237,7 +237,7 @@ function ButtonEdit( props ) {
 			<div
 				{ ...blockProps }
 				className={ classnames( blockProps.className, {
-					[ `wp-block-button__width-${ width }` ]: width,
+					[ `has-custom-width wp-block-button__width-${ width }` ]: width,
 				} ) }
 			>
 				<RichText

packages/block-library/src/button/style.scss

@@ -34,32 +34,27 @@ $blocks-button__height: 3.1em;
 }
 
 .wp-block-button {
-	&.wp-block-button__width-25 {
-		width: 25%;
+	&.has-custom-width {
+		max-width: none;
 		.wp-block-button__link {
 			width: 100%;
 		}
 	}
 
+	&.wp-block-button__width-25 {
+		width: 25%;
+	}
+
 	&.wp-block-button__width-50 {
 		width: 50%;
-		.wp-block-button__link {
-			width: 100%;
-		}
 	}
 
 	&.wp-block-button__width-75 {
 		width: 75%;
-		.wp-block-button__link {
-			width: 100%;
-		}
 	}
 
 	&.wp-block-button__width-100 {
 		width: 100%;
-		.wp-block-button__link {
-			width: 100%;
-		}
 	}
 }