Restore missing codecept.multiple.js file from test/data/sandbox

Co-authored-by: kobenguyent <7845001+kobenguyent@users.noreply.github.com>

Author: Copilot

test/data/sandbox/codecept.multiple.js

@@ -0,0 +1,50 @@
+exports.config = {
+  tests: './*_test.multiple.js',
+  timeout: 10000,
+  output: './output',
+  helpers: {
+    FakeDriver: {
+      require: '../fake_driver',
+      browser: 'dummy',
+      windowSize: 'maximize',
+    },
+  },
+
+  multiple: {
+    default: {
+      browsers: [
+        'chrome',
+        { browser: 'firefox' },
+      ],
+    },
+    mobile: {
+      browsers: [
+        'android',
+        { browser: 'safari', windowSize: 'maximize' },
+        { browser: 'chrome', windowSize: 'maximize' },
+        { browser: 'safari', windowSize: '1200x840' },
+      ],
+    },
+    grep: {
+      grep: '@grep',
+      browsers: [
+        'chrome',
+        { browser: 'firefox', windowSize: '1200x840' },
+      ],
+    },
+    test: {
+      tests: './*_test_override.multiple.js',
+      browsers: [
+        'chrome',
+        { browser: 'firefox', windowSize: '1200x840' },
+      ],
+    },
+    chunks: {
+      chunks: 2,
+    },
+  },
+  include: {},
+  bootstrap: false,
+  mocha: {},
+  name: 'sandbox',
+};