CI: Intermittent connection timeouts to www.gstatic.com

[moreati]

The test "run get_url with specially-sourced python" fails sometimes because a connection timeout occurs to www.gstatic.com. There probably isn't a good reason for this test to perform an (external) HTTP. Another function could be called, that's more self contained.

TASK [run get_url with specially-sourced python url=http://www.gstatic.com/generate_204, status_code=[204]] ***
Sunday 06 October 2024  10:11:32 +0000 (0:00:00.171)       0:03:25.398 ******** 
ok: [target-debian10-4]
ok: [target-debian9-3]
ok: [target-ubuntu1804-6]
ok: [target-debian11-5]
ok: [target-ubuntu2004-7]
ok: [target-centos8-2]
fatal: [target-centos7-1]: FAILED! => changed=false 
  elapsed: 30
  msg: 'Status code was -1 and not [204]: Connection failure: timed out'
  redirected: false
  status: -1
  url: http://www.gstatic.com/generate_204

Contributes to #1058