need .net 6 installed for release-notes

Author: Mpdreamz

.github/workflows/bootstrap/action.yml

@@ -13,8 +13,9 @@ runs:
           
     # Install .NET version as mandated by global.json
     - uses: actions/setup-dotnet@v4
-      with:
-        global-json-file: global.json
+      with: |
+        8.0.x
+        6.0.x
 
     # Setup git config
     - uses: elastic/oblt-actions/git/setup@v1