http: return Content-Length header for HEADs

[qwerzl]

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

Fixes: #56680

[nodejs-github-bot]

Review requested:

• @nodejs/http
• @nodejs/net

[geeksilva97]

Can you add a test that covers this change?

[codecov]

Codecov Report

Attention: Patch coverage is 50.00000% with 1 line in your changes missing coverage. Please review.

Project coverage is 89.20%. Comparing base (fdad2fa) to head (4183136).
Report is 9 commits behind head on main.

Files with missing lines	Patch %	Lines
lib/_http_outgoing.js	50.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #56681      +/-   ##
==========================================
- Coverage   89.20%   89.20%   -0.01%     
==========================================
  Files         662      662              
  Lines      191899   191899              
  Branches    36940    36935       -5     
==========================================
- Hits       171184   171183       -1     
- Misses      13546    13551       +5     
+ Partials     7169     7165       -4     

Files with missing lines	Coverage Δ
lib/_http_outgoing.js	95.15% <50.00%> (-0.08%)	⬇️

... and 39 files with indirect coverage changes

[qwerzl]

Can you add a test that covers this change?

@geeksilva97 Sure! I've modified the test file for HEADs to make sure that Content-Length is received. Also I've changed the message of the first commit to adhere to the guideline.