[breadboard-web] Stop raising exception if Python boards fail to load (…

…breadboard-ai#621)

Unblocks developers that don't have a Python environment set up that can
run breadboard-python.

Co-authored-by: Kevin Xiao <kevxiao@google.com>

packages/breadboard-web/src/make-graphs.ts

@@ -116,7 +116,7 @@ async function savePythonBoard(
 
     return manifestEntry;
   } catch (e) {
-    throw new Error(`Error loading ${filePath}: ${e}`);
+    console.error(`Error loading ${filePath}: ${e}`);
   }
 }