Fix dead links that use the DISTRO macro

After introducing the DISTRO_LATEST_TAG and DISTRO_REL_LATEST_TAG
macros, use them in links that currently use DISTRO/DISTRO_REL_TAG. When
building for the tip of a branch, this will replace the current A.B.999
in links to the latest existing tag.

The links were found across the documentation by running 'grep -r
"http.*5\.2\.999"' inside the _build/html output after building the
docs.

[YOCTO #14802]

(From yocto-docs rev: d1f3616b373334a5aa75ad7874f05ee4b0e6591f)

Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
(cherry picked from commit 29be069ebbf2c55d72fc51d99ed5a558af37c05e)
Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

documentation/dev-manual/qemu.rst

@@ -75,7 +75,7 @@ available. Follow these general steps to run QEMU:
       your :term:`Build Directory`.
 
    -  If you have not built an image, you can go to the
-      :yocto_dl:`machines/qemu </releases/yocto/yocto-&DISTRO;/machines/qemu/>` area and download a
+      :yocto_dl:`machines/qemu </releases/yocto/&DISTRO_REL_LATEST_TAG;/machines/qemu/>` area and download a
       pre-built image that matches your architecture and can be run on
       QEMU.
 

documentation/dev-manual/start.rst

@@ -615,7 +615,7 @@ Accessing Source Archives
 The Yocto Project also provides source archives of its releases, which
 are available on :yocto_dl:`/releases/yocto/`. Then, choose the subdirectory
 containing the release you wish to use, for example
-:yocto_dl:`yocto-&DISTRO; </releases/yocto/yocto-&DISTRO;/>`.
+:yocto_dl:`&DISTRO_REL_LATEST_TAG; </releases/yocto/&DISTRO_REL_LATEST_TAG;/>`.
 
 You will find there source archives of individual components (if you wish
 to use them individually), and of the corresponding Poky release bundling