Make workflows work in fork

Author: tstellar

.github/workflows/issue-release-workflow.yml

@@ -60,7 +60,6 @@ jobs:
       - name: Fetch LLVM sources
         uses: actions/checkout@v2
         with:
-          repository: llvm/llvm-project
           # GitHub stores the token used for checkout and uses it for pushes
           # too, but we want to use a different token for pushing, so we need
           # to disable persist-credentials here.