http: return Content-Length header for HEADs

In the current http library, all responses without body will not return
the Content-Length header.

Fixes: #56680

lib/_http_outgoing.js

@@ -547,7 +547,7 @@ function _storeHeader(firstLine, headers) {
   }
 
   if (!state.contLen && !state.te) {
-    if (!this._hasBody) {
+    if (!this._hasBody && this.req.method !== 'HEAD') {
       // Make sure we don't end the 0\r\n\r\n at the end of the message.
       this.chunkedEncoding = false;
     } else if (!this.useChunkedEncodingByDefault) {
@@ -932,7 +932,7 @@ function strictContentLength(msg) {
   return (
     msg.strictContentLength &&
     msg._contentLength != null &&
-    msg._hasBody &&
+    (msg._hasBody || msg.req.method === 'HEAD') &&
     !msg._removedContLen &&
     !msg.chunkedEncoding &&
     !msg.hasHeader('transfer-encoding')