fix(install): don't cache json exports of JSR packages (for now) (denoland#26530)

Temporary fix for denoland#26509, so people don't get errors.

Author: nathanwhit

cli/tools/registry/pm/cache_deps.rs

@@ -90,8 +90,13 @@ pub async fn cache_top_level_deps(
     while let Some(info_future) = info_futures.next().await {
       if let Some((specifier, info)) = info_future {
         let exports = info.exports();
-        for (k, _) in exports {
+        for (k, v) in exports {
           if let Ok(spec) = specifier.join(k) {
+            if v.ends_with(".json") {
+              // TODO(nathanwhit): this should work, there's a bug with
+              // json roots in deno_graph. skip it for now
+              continue;
+            }
             roots.push(spec);
           }
         }