Update azure-pipelines-mirror-within-azdo.yml for 8.0 (#56457)

Author: BrennanConroy

.azure/pipelines/azure-pipelines-mirror-within-azdo.yml

@@ -3,7 +3,7 @@ trigger:
   batch: true
   branches:
     include:
-    - internal/release/6.0
+    - internal/release/8.0
 
 parameters:
 # Run the pipeline manually (usually disallowed)