Quick fix: remove unnecessary stack catch

[pq]

Follow-up from: #55721 (comment), It'd be nice to have a fix (or at least assist) that removes the unnecessary stack catch in code like:

try { } catch(e, _) {
  print(e);
}

producing:

try { } catch(e) {
  print(e);
}

@bwilkerson: if this is a fix, I guess we'd want a diagnostic for what's essentially dead code?