[Github] Add user of issue-write for llvm#170209

So that we can actually test the workflow before comitting into tree.

Author: boomanaiden154

.github/workflows/issue-write.yml

@@ -8,6 +8,7 @@ on:
       - "PR Request Release Note"
       - "Code lint"
       - "CI Checks"
+      - "Test Issue Write"
     types:
       - completed