docs: remove out-of-date versions doc

It seems nobody is interested in maintaining this info, and nobody seems
to complain. We already have more or less the same information in our
release-notes, so let's just redirect users there instead.

Users interested in archeology can look through the git history for the
information that's missing.

Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/4222
Reviewed-by: Adam Jackson <ajax@redhat.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/10451>

docs/conf.py

@@ -146,6 +146,7 @@ html_redirects = [
   ('gallium/drivers/zink', 'drivers/zink.html'),
   ('llvmpipe', 'drivers/llvmpipe.html'),
   ('postprocess', 'gallium/postprocess.html'),
+  ('versions', 'relnotes.html'),
   ('vmware-guest', 'drivers/vmware-guest.html'),
   ('webmaster', 'https://www.mesa3d.org/website/'),
 ]

docs/relnotes.rst

@@ -300,8 +300,8 @@ The release notes summarize what's new or changed in each Mesa release.
 -  :doc:`6.4.1 release notes <relnotes/6.4.1>`
 -  :doc:`6.4 release notes <relnotes/6.4>`
 
-Versions of Mesa prior to 6.4 are summarized in the :doc:`versions
-file <versions>` and the following release notes.
+Versions of Mesa prior to 6.4 are summarized in the following
+release notes, or in the `old docs`_.
 
 -  `6.3.2 release notes <relnotes/6.3.2>`__
 -  `6.3.1 release notes <relnotes/6.3.1>`__
@@ -629,4 +629,5 @@ file <versions>` and the following release notes.
    relnotes/6.4.2
    relnotes/6.4.1
    relnotes/6.4
-   Older Versions <versions>
+
+.. _old docs: https://gitlab.freedesktop.org/mesa/mesa/-/blob/mesa-21.0.0/docs/versions.rst