Fix axe failure

- role="presentation" wasn't the correct way to fix the jsx/a11y lint complaint and has actual screen reader ramifications we don't want

- After discussing with trevor, the jsx/a11y lint is over-zealous in this case, the end-behavior works better for users with tabIndex and onKeydown, and the rule can be disabled

src/components/code/__snapshots__/code_block.test.tsx.snap

@@ -47,7 +47,6 @@ exports[`EuiCodeBlock full screen displays content in fullscreen mode 1`] = `
   <pre
     className="euiCodeBlock__pre euiCodeBlock__pre--whiteSpacePreWrap"
     onKeyDown={[Function]}
-    role="presentation"
     tabIndex={0}
   >
     <code
@@ -762,7 +761,6 @@ exports[`EuiCodeBlock virtualization renders a virtualized code block 1`] = `
   >
     <pre
       class="euiCodeBlock__pre euiCodeBlock__pre--whiteSpacePreWrap euiCodeBlock__pre--isVirtualized"
-      role="presentation"
       style="position:relative;height:600px;width:600px;overflow:auto;-webkit-overflow-scrolling:touch;will-change:transform;direction:ltr"
       tabindex="0"
     >

src/components/code/code_block.tsx

@@ -40,6 +40,10 @@ import {
   highlightByLine,
 } from './utils';
 
+/* eslint-disable jsx-a11y/no-noninteractive-element-interactions */
+// We're disabling the above a11y lint rule because it's valid for a tabIndex={0} element to have an onKeyDown event listener
+// The onKeyDown is an enhancement for keyboard users, and the tabIndex enables overflow scrolling for keyboard users and enhances focus for screen reader users
+
 // eslint-disable-next-line local/forward-ref
 const virtualizedOuterElement = ({
   className,
@@ -52,7 +56,6 @@ const virtualizedOuterElement = ({
         ref={ref}
         className={className}
         tabIndex={0}
-        role="presentation"
         onKeyDown={onKeyDown}
       />
     ))
@@ -386,12 +389,7 @@ export const EuiCodeBlock: FunctionComponent<EuiCodeBlockProps> = ({
                   )}
                 </EuiAutoSizer>
               ) : (
-                <pre
-                  className={preClasses}
-                  tabIndex={0}
-                  role="presentation"
-                  onKeyDown={onKeyDown}
-                >
+                <pre className={preClasses} tabIndex={0} onKeyDown={onKeyDown}>
                   <code {...codeProps}>{content}</code>
                 </pre>
               )}