Remove unused git-mentoring mailing list

This commit removes the details,
about the [email protected] mailing list.

Reason: This mentoring mailing list is no longer actively used.
New contributors often use the main Git mailing list,
their queries almost always gets answered.

Signed-off-by: K Jayatheerth <[email protected]>

Author: jayatheerthkulkarni

Documentation/MyFirstContribution.adoc

@@ -40,14 +40,6 @@ the list by sending an email to <[email protected]>
 The https://lore.kernel.org/git[archive] of this mailing list is
 available to view in a browser.
 
-==== https://groups.google.com/forum/#!forum/git-mentoring[[email protected]]
-
-This mailing list is targeted to new contributors and was created as a place to
-post questions and receive answers outside of the public eye of the main list.
-Veteran contributors who are especially interested in helping mentor newcomers
-are present on the list. In order to avoid search indexers, group membership is
-required to view messages; anyone can join and no approval is required.
-
 ==== https://web.libera.chat/#git-devel[#git-devel] on Libera Chat
 
 This IRC channel is for conversations between Git contributors. If someone is