Performance Profiler: match code font size in recommendations (#112371)

* Performance Profiler: match inline code font size in recommendations

* fix: match inline code font size with surrounding text using inherit

* fix: match code block font size with surrounding text

The oversized recommendation code block came from <pre> computing to
16px while the surrounding prose is 14px; font-size: inherit on <code>
copied that 16px. Give <pre> font-size: inherit so the block matches its
container, the same way inline code already does.

Author: gavande1

client/dashboard/sites/performance/performance-insight.scss

@@ -1,8 +1,13 @@
 @import "@wordpress/base-styles/variables";
 
 .performance-insight__markdown {
+	code {
+		font-size: inherit;
+	}
+
 	pre:has(code) {
 		max-width: 100%;
+		font-size: inherit;
 		padding: $grid-unit-20;
 		border-radius: $radius-small;
 		background-color: var( --dashboard-inline-code__background-color, #f0f0f1 );

client/performance-profiler/components/insights-section/style.scss

@@ -185,6 +185,11 @@
 				.content {
 					flex: 1 1 500px;
 
+					pre,
+					code {
+						font-size: inherit;
+					}
+
 					&:only-child {
 						flex: 0 1 700px;
 						max-width: 700px; // If elements are wider, e.g. code blocks, there will be a horizontal scroll