Replace process lib with os lib for platform check

Author: mgsium

extensions/ql-vscode/src/extension.ts

@@ -16,7 +16,6 @@ import {
 import { LanguageClient } from 'vscode-languageclient';
 import * as os from 'os';
 import * as path from 'path';
-import process from 'process';
 import { testExplorerExtensionId, TestHub } from 'vscode-test-adapter-api';
 
 import { AstViewer } from './astViewer';
@@ -502,7 +501,7 @@ async function activateWithInstalledDistribution(
         let resolved;
         try {
           let queryPath: string = selectedQuery.path;
-          if (platform.process === 'win32') {
+          if (os.type() === 'Windows_NT') {
             // replaces leading '/' in the query path if followed by a windows drive letter
             queryPath = queryPath.replace(/^\/([a-zA-Z]:)/, '$1');
           }