Button Block: Change text-decoration style to low specificity

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

@@ -8,7 +8,6 @@ $blocks-block__margin: 0.5em;
 	cursor: pointer;
 	display: inline-block;
 	text-align: center;
-	text-decoration: none;
 	word-break: break-word; // overflow-wrap doesn't work well if a link is wrapped in the div, so use word-break here.
 	box-sizing: border-box;
 
@@ -32,6 +31,9 @@ $blocks-block__margin: 0.5em;
 // These rules are set to zero specificity to keep the default styles for buttons.
 // They are needed for backwards compatibility.
 :where(.wp-block-button__link) {
+	// This needs a low specificity so it won't override the rules from the button element if defined in theme.json.
+	text-decoration: none;
+
 	// 100% causes an oval, but any explicit but really high value retains the pill shape.
 	border-radius: 9999px;