migration-guides: add testing notes

(From yocto-docs rev: cd71d0406c96b44cc872f9eb4c8604bcdd62fed6)

Signed-off-by: Ross Burton <ross.burton@arm.com>
Reviewed-by: Michael Opdenacker <michael.opdenacker@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

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

@@ -139,6 +139,21 @@ New Features / Enhancements in 4.3
       <qa-check-unimplemented-ptest>` infrastructure to detect package sources
       with unit tests but no implemented ptests in the recipe.
 
+   -  A new task to perform recipe-wide QA checks was added: ``do_recipe_qa``.
+
+   -  New build-time checks for set :term:`SUMMARY`, :term:`HOMEPAGE`, and
+      :term:`RECIPE_MAINTAINER` fields was added, and enabled for the core
+      recipes.
+
+   -  The ``parselogs`` runtime test was rewritten.  Notably it no longer uses
+      regular expressions, which may mean custom patterns need updating.
+
+   -  A self-test to validate that the :term:`SPDX` manifests generated by
+      image builds are valid was added.
+
+   -  The ``QEMU_USE_SLIRP`` variable has been replaced by adding ``slirp`` to
+      ``TEST_RUNQEMUPARAMS``.
+
 -  Utility script changes:
 
    -  New ``scripts/patchtest`` utility to check patches to the