ref-manual/system-requirements.rst: update supported distributions

Update the distributions to match the list of workers on the
Autobuilder. This list was generated with the help of
yocto-autobuilder-helper/scripts/yocto-supported-distros.

Also:

- Sort the lists alphabetically.
- Decrease spacing between entries for readability.

(From yocto-docs rev: 378bceec8f5a57d4961df178c141f627e48f0235)

Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

documentation/ref-manual/system-requirements.rst

@@ -58,44 +58,40 @@ Supported Linux Distributions
 Currently, the &DISTRO; release ("&DISTRO_NAME;") of the Yocto Project is
 supported on the following distributions:
 
--  Ubuntu 22.04 (LTS)
-
--  Ubuntu 24.04 (LTS)
-
--  Ubuntu 24.10
+..
+   Can be generated with yocto-autobuilder-helper's scripts/yocto-supported-distros:
+   yocto-supported-distros --release walnascar --config yocto-autobuilder2/config.py --output-format docs --poky-distros
 
+-  AlmaLinux 8
+-  AlmaLinux 9
+-  CentOS Stream 9
+-  Debian 11
+-  Debian 12
 -  Fedora 39
-
 -  Fedora 40
-
 -  Fedora 41
-
--  CentOS Stream 9
-
--  Debian GNU/Linux 11 (Bullseye)
-
--  Debian GNU/Linux 12 (Bookworm)
-
 -  OpenSUSE Leap 15.5
-
 -  OpenSUSE Leap 15.6
-
--  AlmaLinux 8
-
--  AlmaLinux 9
-
--  Rocky 8
-
--  Rocky 9
+-  Rocky Linux 8
+-  Rocky Linux 9
+-  Ubuntu 20.04 (LTS)
+-  Ubuntu 22.04 (LTS)
+-  Ubuntu 24.04 (LTS)
+-  Ubuntu 24.10
 
 The following distribution versions are still tested, even though the
 organizations publishing them no longer make updates publicly available:
 
--  Ubuntu 18.04 (LTS)
+..
+   This list contains EOL distros that are still tested on the Autobuilder
+   (meaning there are running workers).
+   See https://endoflife.date for information of EOL releases.
 
+-  Fedora 39
+-  Fedora 40
+-  OpenSUSE Leap 15.5
 -  Ubuntu 20.04 (LTS)
-
--  Ubuntu 23.04
+-  Ubuntu 24.10
 
 Note that the Yocto Project doesn't have access to private updates
 that some of these versions may have. Therefore, our testing has
@@ -106,7 +102,11 @@ tools, such as python.
 Finally, here are the distribution versions which were previously
 tested on former revisions of "&DISTRO_NAME;", but no longer are:
 
-*This list is currently empty*
+..
+   Can be generated with yocto-autobuilder-helper's scripts/yocto-supported-distros:
+   yocto-supported-distros --release walnascar --config yocto-autobuilder2/config.py --output-format docs --old-distros
+
+-  Ubuntu 23.04
 
 .. note::