src: fix compiler warnings in node_report_module

Currently, the following compiler warnings are generated:
../src/node_report_module.cc:
In function ‘void report::ShouldReportOnFatalError(
    const v8::FunctionCallbackInfo<v8::Value>&)’:
../src/node_report_module.cc:132:16: warning:
unused variable ‘env’ [-Wunused-variable]
  132 |   Environment* env = Environment::GetCurrent(info);
      |                ^~~
../src/node_report_module.cc:
In function ‘void report::SetReportOnFatalError(
    const v8::FunctionCallbackInfo<v8::Value>&)’:
../src/node_report_module.cc:138:16: warning:
unused variable ‘env’ [-Wunused-variable]
  138 |   Environment* env = Environment::GetCurrent(info);
      |                ^~~

This commit removes the unused variables.

PR-URL: https://github.com/nodejs/node/pull/32498


Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: Jiawen Geng <technicalcute@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: James M Snell <jasnell@gmail.com>