Pull Request for Issue #36869

Summary of Changes

Make the headers check before the update download proxy aware by passing it via HttpFactory

Testing Instructions

First test

• install 3.10.4
• Apply this patch using com_patchtester
• try to update to 3.10.5 using the default update channel. (please note the patch will be reverted by the update)

Second test

• install 3.10.4
• Apply this patch using com_patchtester
• set the update server of this PR here: https://ci.joomla.org/artifacts/joomla/joomla-cms/3.10-dev/36886/downloads/51239/pr_list.xml
• update to the 3.10.6-dev package that includes this patch

Third test

• install 3.10.4
• configure an proxy within the global configuration
• Apply this patch using com_patchtester
• try to update to 3.10.5 using the default update channel. (please note the patch will be reverted by the update)

Actual result BEFORE applying this Pull Request

Before the patch you can not update using the proxy setting as the get_headers call fails as it does not go via the proxy.

Expected result AFTER applying this Pull Request

Before and after the patch you can update without proxy but with that patch also with the proxy as we now go via the HTTPFactory vs get_headers directly.

Documentation Changes Required

none

cc @ThomasGarcia05 @richard67 @HLeithner