Update Aspire branding from 13.0 to 13.1 (#12527)

* Initial plan

* Update Aspire branding from 13.0 to 13.1 - core files and templates

Co-authored-by: joperezr <13854455+joperezr@users.noreply.github.com>

* Update test constant for AspireVersionNext to 13.1

Co-authored-by: joperezr <13854455+joperezr@users.noreply.github.com>

* Undo template changes

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: joperezr <13854455+joperezr@users.noreply.github.com>
Co-authored-by: Jose Perez Rodriguez <joperezr@microsoft.com>

Author: Copilot

.github/policies/milestoneAssignment.prClosed.yml

@@ -16,7 +16,7 @@ configuration:
           branch: main
       then:
       - addMilestone:
-          milestone: 13.0
+          milestone: 13.1
       description: '[Milestone Assignments] Assign Milestone to PRs merged to the `main` branch'
     - if:
       - payloadType: Pull_Request

eng/Versions.props

@@ -2,7 +2,7 @@
   <PropertyGroup>
     <!-- This repo version -->
     <MajorVersion>13</MajorVersion>
-    <MinorVersion>0</MinorVersion>
+    <MinorVersion>1</MinorVersion>
     <PatchVersion>0</PatchVersion>
     <VersionPrefix>$(MajorVersion).$(MinorVersion).$(PatchVersion)</VersionPrefix>
     <PreReleaseVersionLabel>preview.1</PreReleaseVersionLabel>