Fix workflow: Use github.token instead of GITHUB_TOKEN secret

- github.token is automatically provided by GitHub Actions
- GITHUB_TOKEN is a reserved secret name that causes conflicts
- This fixes the workflow validation error

Author: spbolton

.github/workflows/issue_comp_link-issue-to-pr.yml

@@ -27,16 +27,11 @@ on:
         description: 'PR merged status'
         required: true
         type: string
-    secrets:
-      GITHUB_TOKEN:
-        description: 'GitHub token'
-        required: true
-
 jobs:
   link-issue:
     runs-on: ubuntu-latest
     env:
-      GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      GH_TOKEN: ${{ github.token }}
 
     steps:
       - name: Checkout code

.github/workflows/issue_open-pr.yml

@@ -15,5 +15,3 @@ jobs:
       pr_body: ${{ github.event.pull_request.body }}
       pr_author: ${{ github.event.pull_request.user.login }}
       pr_merged: ${{ github.event.pull_request.merged }}
-    secrets:
-      GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}