[release/9.0] Move default build images to macos 15 (and xcode 16) (#120589) (#122422)

(cherry picked from commit eaafd7c)
(cherry picked from commit 1905046)

---------

Co-authored-by: Eric StJohn <ericstj@microsoft.com>
Co-authored-by: Matous Kozak <matouskozak@seznam.cz>
Co-authored-by: Filip Navara <filip.navara@gmail.com>

Author: 4 people

eng/pipelines/common/xplat-setup.yml

@@ -156,6 +156,9 @@ jobs:
         container: ${{ parameters.container }}
 
     ${{ if eq(parameters.jobParameters.pool, '') }}:
+      # N.B.: We should always be building on the latest available version of our build platform.
+      # Each of these queues should be the latest version or have a tracking issue if the latest version
+      # does not work for some reason.
       pool:
         # Public Linux Build Pool
         ${{ if and(or(in(parameters.osGroup, 'linux', 'freebsd', 'android', 'tizen'), eq(parameters.jobParameters.hostedOs, 'linux')), eq(variables['System.TeamProject'], 'public')) }}:
@@ -170,7 +173,7 @@ jobs:
 
         # OSX Public Build Pool (we don't have on-prem OSX BuildPool).
         ${{ if and(in(parameters.osGroup, 'osx', 'maccatalyst', 'ios', 'iossimulator', 'tvos', 'tvossimulator'), eq(variables['System.TeamProject'], 'public')) }}:
-          vmImage: 'macos-13'
+          vmImage: 'macos-15'
 
         # OSX Internal Pool
         ${{ if and(in(parameters.osGroup, 'osx', 'maccatalyst', 'ios', 'iossimulator', 'tvos', 'tvossimulator'), ne(variables['System.TeamProject'], 'public')) }}: