dev/release.sh: improve instruction for pushing the tag

'git push --follow-tags' does a little too much, any spurious tag
object that the releaser have in their local repository will come
along, even though they have nothing to do with the commits being
pushed.

Therefore, we modify the instructions to show a separate and explicit
push of the release tag.

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from openssl#13159)

dev/release.sh

@@ -556,10 +556,12 @@ Push them to github, make PRs from them and have them approved:
 
 When merging them into the main repository, do it like this:
 
-    git push --follow-tags openssl-git@git.openssl.org:openssl.git \\
+    git push openssl-git@git.openssl.org:openssl.git \\
         $tmp_release_branch:$release_branch
     git push openssl-git@git.openssl.org:openssl.git \\
         $tmp_update_branch:$update_branch
+    git push openssl-git@git.openssl.org:openssl.git \\
+        $tag
 EOF
 else
 cat <<EOF
@@ -570,8 +572,10 @@ Push it to github, make a PR from it and have it approved:
 
 When merging it into the main repository, do it like this:
 
-    git push --follow-tags openssl-git@git.openssl.org:openssl.git \\
+    git push openssl-git@git.openssl.org:openssl.git \\
         $tmp_release_branch:$release_branch
+    git push openssl-git@git.openssl.org:openssl.git \\
+        $tag
 EOF
 fi