Prevent Sphinx 4 and later from creating subdirectories, which
the build scripts are not equipped to deal with.

Taken from upstream:
https://gitlab.com/qemu-project/qemu/-/issues/256
https://gitlab.com/qemu-project/qemu/-/commit/269a7e97865cb863c9ca19e5f2e6a40ac9eddf82

diff --git a/docs/conf.py b/docs/conf.py
--- a/docs/conf.py
+++ b/docs/conf.py
@@ -279,6 +279,7 @@
      ['Stefan Hajnoczi <stefanha@redhat.com>',
       'Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>'], 1),
 ]
+man_make_section_directory = False
 
 # -- Options for Texinfo output -------------------------------------------
 
type='hidden' name='id' value='d582b399781f6fd80c63d07746524196603972e4'/><select name='h' onchange='this.form.submit();'>
<option value='koszko' selected='selected'>koszko</option>
<option value='koszko-scripts'>koszko-scripts</option>
</select> <input type='submit' value='switch'/></form></td></tr>
<tr><td class='sub'>Wojtek's customized Guix</td><td class='sub right'></td></tr></table>
<table class='tabs'><tr><td>
<a href='/guix/about/'>about</a><a href='/guix/'>summary</a><a href='/guix/refs/?id=d582b399781f6fd80c63d07746524196603972e4'>refs</a><a class='active' href='/guix/log/tests/services'>log</a><a href='/guix/tree/tests/services?id=d582b399781f6fd80c63d07746524196603972e4'>tree</a><a href='/guix/commit/tests/services?id=d582b399781f6fd80c63d07746524196603972e4'>commit</a><a href='/guix/diff/tests/services?id=d582b399781f6fd80c63d07746524196603972e4'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/tests/services'>
<input type='hidden' name='id' value='d582b399781f6fd80c63d07746524196603972e4'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=d582b399781f6fd80c63d07746524196603972e4'>root</a>/<a href='/guix/log/tests?id=d582b399781f6fd80c63d07746524196603972e4'>tests</a>/<a href='/guix/log/tests/services?id=d582b399781f6fd80c63d07746524196603972e4'>services</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/tests/services?id=d582b399781f6fd80c63d07746524196603972e4&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2021-08-02 17:23:30 -0400'>2021-08-02</span></td><td><a href='/guix/commit/tests/services?id=10f554700c417b84c22c56fdd007567a52c45d75'>Reinstate "services: Add a service for Jami."</a><span class='msg-avail'>...</span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2021-08-02 15:48:59 -0400'>2021-08-02</span></td><td><a href='/guix/commit/tests/services?id=4673f817938d9d2b1b40a072ab2e0c44a32ccc97'>Revert "services: Add a service for Jami."</a><span class='msg-avail'>...</span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2021-08-02 15:15:02 -0400'>2021-08-02</span></td><td><a href='/guix/commit/tests/services?id=69dcc24c9f0cdfea674eb690e7755d26a25ced2b'>services: Add a service for Jami.</a><span class='msg-avail'>...</span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2021-06-29 12:37:33 +0200'>2021-06-29</span></td><td><a href='/guix/commit/tests/services?id=2ad896751c8f7104f139c3fd43cd632fd428ccd5'>services: configuration: Allow specifying prefix for serializer names.</a><span class='msg-avail'>...</span></td><td>Xinglu Chen</td></tr>
<tr><td><span title='2021-05-17 23:27:39 -0400'>2021-05-17</span></td><td><a href='/guix/commit/tests/services?id=b7297d66c58b4fe2c153dce4f1069235269cd005'>services: configuration: Add a define-maybe/no-serialization syntax.</a><span class='msg-avail'>...</span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2021-05-08 01:04:31 -0400'>2021-05-08</span></td><td><a href='/guix/commit/tests/services?id=a77e3a5846d8b4b4b8d0fe4887d1ee17340971e0'>services: configuration: Add tests.</a><span class='msg-avail'>...</span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2021-02-12 15:11:36 +0800'>2021-02-12</span></td><td><a href='/guix/commit/tests/services?id=db6b9d2f4bc59511904e8c1412d0257675c46095'>services: Add transmission-daemon service.</a><span class='msg-avail'>...</span></td><td>Simon South</td></tr>
<tr><td><span title='2020-08-02 15:54:37 +0300'>2020-08-02</span></td><td><a href='/guix/commit/tests/services?id=587e0d911dfff81647015e89847084b606e68f71'>services: Add zram-device-service.</a><span class='msg-avail'>...</span></td><td>Efraim Flashner</td></tr>