migration-guides: replace broken link with archive links

Replace broken link with working archives found on
https://web.archive.org/.

Suggested-by: Quentin Schulz <quentin.schulz@cherry.de>
(From yocto-docs rev: 9db9bf1e64efa4fcce193d7f4ca0c5ca0b1bdaf0)

Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
(cherry picked from commit 3288e85934868917f10d66a9130bbdfa5e0ff763)
[AG: conflicts: remove applied hunks for non-existing files]
Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
Signed-off-by: Paul Barker <paul@pbarker.dev>

documentation/migration-guides/release-notes-4.3.rst

@@ -73,7 +73,7 @@ New Features / Enhancements in 4.3
      for the latest long-term release (6.1).
 
    - The list of fixed kernel CVEs is updated regularly using data from
-     `linuxkernelcves.com <https://linuxkernelcves.com>`__.
+     `linuxkernelcves.com <https://web.archive.org/web/20240420122324/https://www.linuxkernelcves.com/>`__.
 
    - A ``showconfig`` task was added to the :ref:`ref-classes-cml1` class, to
      easily examine the final generated ``.config`` file.

documentation/migration-guides/release-notes-5.0.rst

@@ -166,7 +166,7 @@ New Features / Enhancements in 5.0
       ``meta/lib/patchtest/tests``) and make a number of improvements to enable
       it to validate patches submitted on the mailing list again. Additionally,
       make it work with the original upstream version of
-      `Patchwork <http://jk.ozlabs.org/projects/patchwork/>`__.
+      `Patchwork <https://web.archive.org/web/20250823174533/http://jk.ozlabs.org/projects/patchwork/>`__.
 
    -  Add an optional ``unimplemented-ptest`` QA warning to detect upstream
       packages with tests, that do not use ptest.