ci: minor fixes to the TSC management workflow (asyncapi#1734)

Co-authored-by: Viacheslav Turovskyi <aeworxet@protonmail.com>
Co-authored-by: Lukasz Gornicki <lpgornicki@gmail.com>

.github/workflows/tsc_management.yml

@@ -1,7 +1,7 @@
 name: TSC Management Workflow
 
 on:
-  pull_request:
+  pull_request_target:
     types: [closed]
     paths:
       - 'MAINTAINERS.yaml'
@@ -90,7 +90,7 @@ jobs:
       - name: Add new TSC members to the team
         uses: actions/github-script@v6
         with:
-          github-token: ${{ secrets.GH_TOKEN }}
+          github-token: ${{ secrets.GH_TOKEN_ORG_ADMIN }}
           script: |
             const newTscMembers = ${{ needs.detect_tsc_membership_changes.outputs.updatedMaintainers }};
             for (const tscMember of newTscMembers) {
@@ -152,7 +152,7 @@ jobs:
       - name: Remove TSC members from the team
         uses: actions/github-script@v6
         with:
-          github-token: ${{ secrets.GH_TOKEN }}
+          github-token: ${{ secrets.GH_TOKEN_ORG_ADMIN }}
           script: |
             const removedMaintainers = ${{ needs.detect_tsc_membership_changes.outputs.updatedMaintainers }};
             for (const maintainer of removedMaintainers) {
@@ -203,7 +203,6 @@ jobs:
       - name: Add Former TSC members to Emeritus.yaml and print
         uses: actions/github-script@v6
         with:
-          github-token: ${{ secrets.GH_TOKEN }}
           script: |
             const fs = require('fs');
             const path = './Emeritus.yaml';
@@ -239,7 +238,8 @@ jobs:
         run: |
           git add .
           git commit -m "Update Emeritus.yaml"
-          git push https://${{ secrets.GH_TOKEN}}@github.com/asyncapi/community update-emeritus-${{ github.run_id }}
+          git remote set-url origin https://x-access-token:${{ secrets.GH_TOKEN }}@github.com/asyncapi/community.git
+          git push origin update-emeritus-${{ github.run_id }}
 
       - name: Create PR
         run: |