When visiting certain websites in Epiphany, some background events
unexpectedly download files. Those files are always zero-size.
Revisiting the webpage results in getting the same. (Newer files get a
number index in their names to prevent them from overriding the
previously downloaded files.)

The file downloads seem related to network requests to the resources
with the same name as the file. Those resources have no content. It
appears intentional (e.g. for tracking) and not a misconfiguration. If
you do not observe the issue, turn off the "Block Advertisements"
feature in Epiphany.

Michael Catanzaro suggested that it seems to be the bug in `libsoup`
before version 3.4. The patch by Vivien Kraus from issue #67424 allows
updating `libsoup` to 3.4.4. I confirm that rebuilding Epiphany against
that version stops unexpected downloads.

Michael Catanzaro also suggested updating Epiphany to 44.0 or newer. I
cannot confirm that it is required to fix the apparent or any hidden
issue. (Vivien Kraus sent a patch for updating to 44.7 in issue
#67162.)

Previous discussion:
https://discourse.gnome.org/t/ghost-files-are-downloaded-when-browsing/18119/7?u=riabenko

```
$ LC_ALL=C guix describe
Generation 55	Nov 24 2023 20:06:16	(current)
  guix 9f67681
    repository URL: https://git.savannah.gnu.org/git/guix.git
    branch: master
    commit: 9f67681db15d22f7ede5488315d52b78e357343e
  nonguix de0125a
    repository URL: https://gitlab.com/nonguix/nonguix
    branch: master
    commit: de0125a78318531cc1b55bd7428698e0b342e912
$ epiphany --version
Web 42.4
$ gnome-shell --version
GNOME Shell 42.4
```
`webkitgtk` is 2.40.5. `libsoup` is 3.1.4.

Roman