Fix stuck when using http2 POST Buffer

lib/client.js

@@ -1862,6 +1862,7 @@ function writeH2 (client, session, request) {
       stream.cork()
       stream.write(body)
       stream.uncork()
+      stream.end()
       request.onBodySent(body)
       request.onRequestSent()
     } else if (util.isBlobLike(body)) {

test/http2.js

@@ -17,7 +17,7 @@ const isGreaterThanv20 = gte(process.version.slice(1), '20.0.0')
 // https://github.com/nodejs/node/pull/41735
 const hasPseudoHeadersOrderFix = gte(process.version.slice(1), '16.14.1')
 
-plan(20)
+plan(21)
 
 test('Should support H2 connection', async t => {
   const body = []
@@ -114,6 +114,58 @@ test('Should support H2 connection (headers as array)', async t => {
   t.equal(Buffer.concat(body).toString('utf8'), 'hello h2!')
 })
 
+test('Should support H2 connection(POST Buffer)', async t => {
+  const server = createSecureServer({ ...pem, allowHTTP1: false })
+
+  server.on('stream', async (stream, headers, _flags, rawHeaders) => {
+    t.equal(headers[':method'], 'POST')
+    const reqData = []
+    stream.on('data', chunk => reqData.push(chunk.toString()))
+    await once(stream, 'end')
+    t.equal(reqData.join(''), 'hello!')
+    stream.respond({
+      'content-type': 'text/plain; charset=utf-8',
+      'x-custom-h2': 'hello',
+      ':status': 200
+    })
+    stream.end('hello h2!')
+  })
+
+  server.listen(0)
+  await once(server, 'listening')
+
+  const client = new Client(`https://localhost:${server.address().port}`, {
+    connect: {
+      rejectUnauthorized: false
+    },
+    allowH2: true
+  })
+
+  t.plan(6)
+  t.teardown(server.close.bind(server))
+  t.teardown(client.close.bind(client))
+
+  const sendBody = 'hello!'
+  const body = []
+  console.log(`before request ${sendBody}`)
+  const response = await client.request({
+    path: '/',
+    method: 'POST',
+    body: sendBody
+  })
+  console.log(`after request ${sendBody}`)
+
+  response.body.on('data', chunk => {
+    body.push(chunk)
+  })
+
+  await once(response.body, 'end')
+  t.equal(response.statusCode, 200)
+  t.equal(response.headers['content-type'], 'text/plain; charset=utf-8')
+  t.equal(response.headers['x-custom-h2'], 'hello')
+  t.equal(Buffer.concat(body).toString('utf8'), 'hello h2!')
+})
+
 test('Should support H2 GOAWAY (server-side)', async t => {
   const body = []
   const server = createSecureServer(pem)