fix(maps): avoid 404 on keyless Google tiles-token probe (#1066)

Return an uncached unavailable-token response for keyless Google tile-token requests.

Contribution by @dvilrgamerz.

src/maps/googleTokens.js

@@ -38,6 +38,7 @@ export function createGoogleTokenSource({
         headers: { Accept: 'application/json' },
         cache: 'no-store',
       });
+      if (response.status === 204) return null;
       if (!response.ok) {
         await response.body?.cancel();
         return null;

src/maps/googleTokens.test.mjs

@@ -79,3 +79,12 @@ test('a server that does not offer tokens yields none', async () => {
     assert.equal(await createGoogleTokenSource({ fetchImpl }).token(), null);
   }
 });
+
+test('an empty 204 response explicitly means no Google token is available', async () => {
+  const { calls, fetchImpl } = server([
+    new Response(null, { status: 204, headers: { 'Cache-Control': 'no-store' } }),
+  ]);
+  const tokens = createGoogleTokenSource({ fetchImpl });
+  assert.equal(await tokens.token(), null);
+  assert.deepEqual(calls, [GOOGLE_TOKEN_PATH]);
+});