Create GPU target notification group

* Create GPU target notification group
* Update triagebot.toml

Co-authored-by: 许杰友 Jieyou Xu (Joe) <39484203+jieyouxu@users.noreply.github.com>

Author: apiraino

triagebot.toml

@@ -194,6 +194,11 @@ Hi relnotes-interest-group, this issue/PR could use some help in reviewing /
 adjusting release notes. Could you take a look if available? Thanks <3
 """
 
+[ping.gpu-target]
+message = """\
+Hi GPU experts, this issue/PR could use some guidance on how this should be
+resolved/implemented. Could you take a look if available? Thanks <3
+"""
 
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 # Autolabels