🔇 fix: Hide Button Icons from Screen Readers (#10776)

If you've got a screen reader that is reading out the whole page,
each icon button (i.e., `<button><SVG></button>`) will have both
the button's aria-label read out as well as the title from the
SVG (which is usually just "image").

Since we are pretty good about setting aria-labels, we should instead
use `aria-hidden="true"` on these images, since they are not useful
to be read out.

I don't consider this a comprehensive review of all icons in the app,
but I knocked out all the low hanging fruit in this commit.

client/src/components/Artifacts/DownloadArtifact.tsx

@@ -41,7 +41,11 @@ const DownloadArtifact = ({ artifact }: { artifact: Artifact }) => {
       onClick={handleDownload}
       aria-label={localize('com_ui_download_artifact')}
     >
-      {isDownloaded ? <CircleCheckBig size={16} /> : <Download size={16} />}
+      {isDownloaded ? (
+        <CircleCheckBig size={16} aria-hidden="true" />
+      ) : (
+        <Download size={16} aria-hidden="true" />
+      )}
     </Button>
   );
 };