docs: fix mailing list URL

With the transition to mailman3, the URL of TF-A Tests mailing list
has changed. However, we still refer to the old location, which are
now dead links.

Update all relevant links throughout the documentation.

Change-Id: Ieb7357cc84037c10dd91757feb059b89073a75d8
Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>
Reported-by: Kuohong Wang <kuohong.wang@mediatek.com>
diff --git a/docs/about/contact.rst b/docs/about/contact.rst
index a84dc52..2b1778c 100644
--- a/docs/about/contact.rst
+++ b/docs/about/contact.rst
@@ -26,8 +26,8 @@
 
 --------------
 
-*Copyright (c) 2019, Arm Limited. All rights reserved.*
+*Copyright (c) 2019-2022, Arm Limited. All rights reserved.*
 
 .. _`issue tracker`: https://developer.trustedfirmware.org
-.. _`TF-A-Tests development`: https://lists.trustedfirmware.org/pipermail/tf-a-tests/
-.. _`summary of all the lists`: https://lists.trustedfirmware.org
+.. _`TF-A-Tests development`: https://lists.trustedfirmware.org/mailman3/lists/tf-a-tests.lists.trustedfirmware.org/
+.. _`summary of all the lists`: https://lists.trustedfirmware.org/mailman3/lists/