test: the USB mouse test reads the harness's CRLF output on Windows

A MinGW build of the harness writes every line as \r\n, since its stdout is
in text mode, and the test split on \n alone: each value it compared carried
a \r, all seven cases failed on a Windows checkout, and a real failure among
them would have gone unnoticed. CI's Linux runner never saw it. Splitting on
\r?\n reads both, as 78bf062 did for the C64 screen scan.

Author: SensoriumEmbedded

Source/Teensy/tests/usb-mouse.test.js

@@ -32,7 +32,8 @@ function harness() {
 function run(lines) {
   const ran = spawnSync(harness(), { input: lines.join('\n') + '\n', encoding: 'utf8' });
   assert.equal(ran.status, 0, ran.stderr);
-  return ran.stdout.split('\n').filter(Boolean);
+  // A MinGW build of the harness writes its lines as \r\n: stdout is in text mode there.
+  return ran.stdout.split(/\r?\n/).filter(Boolean);
 }
 
 const report = (dx, dy, buttons = 0) => [`report ${dx} ${dy} ${buttons.toString(16)}`, 'poll'];