Update milestones for September (#63108)

Author: wtgodbe

.github/policies/resourceManagement.yml

@@ -614,7 +614,7 @@ configuration:
       then:
       - removeMilestone
       - addMilestone:
-          milestone: 9.0.7
+          milestone: 9.0.9
       description: '[Milestone Assignments] Assign Milestone to PRs merged to release/9.0 branch'
     - if:
       - payloadType: Pull_Request
@@ -625,7 +625,7 @@ configuration:
       then:
       - removeMilestone
       - addMilestone:
-          milestone: 8.0.18
+          milestone: 8.0.20
       description: '[Milestone Assignments] Assign Milestone to PRs merged to release/8.0 branch'
     - if:
       - payloadType: Issues
@@ -742,3 +742,4 @@ configuration:
       description: '[Infrastructure PRs] Add area-infrastructure label to dependabot update Pull Requests & enable auto-merge'
 onFailure: 
 onSuccess: 
+