cleanup: remove unnecessary require for global Buffer

The Buffer object is globally available in Node.js, so there is no need to explicitly require it.

test/express.json.js

@@ -2,7 +2,6 @@
 
 var assert = require('assert')
 var asyncHooks = tryRequire('async_hooks')
-var Buffer = require('node:buffer').Buffer
 var express = require('..')
 var request = require('supertest')
 

test/express.raw.js

@@ -2,7 +2,6 @@
 
 var assert = require('assert')
 var asyncHooks = tryRequire('async_hooks')
-var Buffer = require('node:buffer').Buffer
 var express = require('..')
 var request = require('supertest')
 

test/express.static.js

@@ -1,7 +1,6 @@
 'use strict'
 
 var assert = require('assert')
-var Buffer = require('node:buffer').Buffer
 var express = require('..')
 var path = require('path')
 var request = require('supertest')

test/express.text.js

@@ -2,7 +2,6 @@
 
 var assert = require('assert')
 var asyncHooks = tryRequire('async_hooks')
-var Buffer = require('node:buffer').Buffer
 var express = require('..')
 var request = require('supertest')
 

test/express.urlencoded.js

@@ -2,7 +2,6 @@
 
 var assert = require('assert')
 var asyncHooks = tryRequire('async_hooks')
-var Buffer = require('node:buffer').Buffer
 var express = require('..')
 var request = require('supertest')
 

test/res.attachment.js

@@ -1,6 +1,5 @@
 'use strict'
 
-var Buffer = require('node:buffer').Buffer
 var express = require('../')
   , request = require('supertest');
 

test/res.download.js

@@ -3,7 +3,6 @@
 var after = require('after');
 var assert = require('assert')
 var asyncHooks = tryRequire('async_hooks')
-var Buffer = require('node:buffer').Buffer
 var express = require('..');
 var path = require('path')
 var request = require('supertest');

test/res.send.js

@@ -1,7 +1,6 @@
 'use strict'
 
 var assert = require('assert')
-var Buffer = require('node:buffer').Buffer
 var express = require('..');
 var methods = require('methods');
 var request = require('supertest');

test/res.sendFile.js

@@ -3,7 +3,6 @@
 var after = require('after');
 var assert = require('assert')
 var asyncHooks = tryRequire('async_hooks')
-var Buffer = require('node:buffer').Buffer
 var express = require('../')
   , request = require('supertest')
 var onFinished = require('on-finished');

test/support/utils.js

@@ -5,7 +5,6 @@
  */
 
 var assert = require('assert');
-var Buffer = require('node:buffer').Buffer
 
 /**
  * Module exports.

test/utils.js

@@ -1,7 +1,6 @@
 'use strict'
 
 var assert = require('assert');
-var Buffer = require('node:buffer').Buffer
 var utils = require('../lib/utils');
 
 describe('utils.etag(body, encoding)', function(){