[Bug]: install-src / list-src fails for qt 6.8.1

[VivienDelmon]

Bug description

When trying to list-src for 6.8.0 or 6.8.1 I get the following error:

PS F:\Qt> aqt list-src  windows 6.8.1
ERROR   : Failed to download checksum for the file 'Updates.xml' from mirrors '['https://download.qt.io']
==============================Suggested follow-up:==============================
* Check your internet connection
* Consider modifying `requests.max_retries_to_retrieve_hash` in settings.ini
* Consider modifying `mirrors.trusted_mirrors` in settings.ini (see https://aqtinstall.readthedocs.io/en/stable/configuration.html#configuration)
usage: aqt [-h] [-c CONFIG]
           {install-qt,install-tool,install-doc,install-example,install-src,list-qt,list-tool,list-doc,list-example,list-src,help,version}
           ...

Another unofficial Qt Installer.
aqt helps you install Qt SDK, tools, examples and others

options:
  -h, --help            show this help message and exit
  -c CONFIG, --config CONFIG
                        Configuration ini file.

subcommands:
  aqt accepts several subcommands:
  install-* subcommands are commands that install components
  list-* subcommands are commands that show available components

  {install-qt,install-tool,install-doc,install-example,install-src,list-qt,list-tool,list-doc,list-example,list-src,help,version}
                        Please refer to each help message by using '--help' with each subcommand

Then, when I try to install it, it also fail (but it work with 6.8.0):

PS F:\Qt> aqt install-src  windows 6.8.1
INFO    : aqtinstall(aqt) v3.1.21 on Python 3.12.8 [CPython MSC v.1942 64 bit (AMD64)]
WARNING : Failed to download checksum for the file 'online/qtsdkrepository/all_os/qt/qt6_681_src_doc_examples/Updates.xml'. This may happen on unofficial mirrors.
ERROR   : Failed to locate XML data for Qt version '6.8.1'.
==============================Suggested follow-up:==============================
* Please use 'aqt list-qt all_os qt' to show versions available.

Expected behavior

A successful 6.8.1 sources deployement

aqt and python version

v3.1.21 on Python 3.12.8 [CPython MSC v.1942 64 bit (AMD64)]

Operating System

Windows

Relevant log output

No response

Code of Conduct

• I agree to follow this project's Code of Conduct

[tsteven4]

The list-src and install-src cases were fixed in #857 f914397, which hasn't been released.

Subsequently the list-src cases were broken by #846 a09b5ce. I expressed concern about this change but couldn't cite an example in the PR https://github.com/miurahr/aqtinstall/pull/846/files#r1889522405.