Regression fixup: respect anchor-check configuration setting

[jayaddison]

Feature or Bugfix

• Bugfix

Purpose

• Fixes a regression introduced by refactoring in Refactor: linkcheck builder: reduce the lifetime of the 'response' variable #11432 : the linkcheck_anchors setting was not being respected.

Detail

• When anchor checking is disabled, the client uses an HTTP HEAD request instead of an HTTP GET request, to reduce network traffic optimization.
• A response to an HTTP HEAD request should not contain response content, but since Refactor: linkcheck builder: reduce the lifetime of the 'response' variable #11432 the linkcheck builder code has been attempting to read content from these responses.

Relates

• May resolve linkcheck failing after Sphinx 7.1.0 release #11542.

[francoisfreitag]

Looking good. Maybe also add a mention to the release note?