lib: remove an unused variable

PR-URL: #23482
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>

lib/internal/bootstrap/node.js

@@ -632,7 +632,9 @@
  const { kExpandStackSymbol } = NativeModule.require('internal/util');
  if (typeof er[kExpandStackSymbol] === 'function')
  er[kExpandStackSymbol]();
- } catch (er) {}
+ } catch {
+ // Nothing to be done about it at this point.
+ }
  return false;
  }