test(imaging): drop /imaging e2e assertion shadowed by the edge proxy

In production the edge proxy fronts /imaging to the imager container, so the
CMS route only answers when reached directly. Asserting it in the shared spec
failed against the public site in all three engines. Its behaviour is covered
by src/lib/imaging-route.test.ts; the e2e spec now only checks the endpoints
that are identical in both topologies (/api/imaging/avatar and the badge).

e2e/imaging/avatar-endpoint.spec.ts

@@ -67,13 +67,10 @@ test("rejects a malformed figure with 400", async ({ request }) => {
 	expect(response.status()).toBe(400);
 });
 
-test("the default /imaging endpoint serves a PNG", async ({ request }) => {
+// NB: the sibling `/imaging` CMS route is intentionally fronted to the imager
-	const response = await request.get(
+// container by the edge proxy in production, so it is not asserted here — it
-		`/imaging?${new URLSearchParams({ figure: FIGURE, img_format: "png" })}`,
+// would only pass when the CMS is reached directly. Its behaviour is covered by
-	);
+// src/lib/imaging-route.test.ts.
-	expect(response.status()).toBe(200);
-	expect(response.headers()["content-type"]).toContain("image/png");
-});
 
 test("the badge endpoint serves an image and revalidates", async ({
 	request,