🔇 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/Endpoints/MinimalIcon.tsx

@@ -47,7 +47,7 @@ const MinimalIcon: React.FC<IconProps> = (props) => {
     [EModelEndpoint.assistants]: { icon: <Sparkles className="icon-sm" />, name: 'Assistant' },
     [EModelEndpoint.azureAssistants]: { icon: <Sparkles className="icon-sm" />, name: 'Assistant' },
     [EModelEndpoint.agents]: {
-      icon: <Feather className="icon-sm" />,
+      icon: <Feather className="icon-sm" aria-hidden="true" />,
       name: props.modelLabel ?? alternateName[EModelEndpoint.agents],
     },
     [EModelEndpoint.bedrock]: {