[INTERNAL] Add message for v3 deprecation (#1184)

JIRA: CPOUI5FOUNDATION-875

---------

Co-authored-by: Matthias Osswald <mat.osswald@sap.com>

Author: d3xter666

README.md

@@ -9,6 +9,8 @@
 [![npm Package Version](https://badge.fury.io/js/%40ui5%2Fbuilder.svg)](https://www.npmjs.com/package/@ui5/builder)
 [![Coverage Status](https://coveralls.io/repos/github/SAP/ui5-builder/badge.svg)](https://coveralls.io/github/SAP/ui5-builder)
 
+> ⚠️ UI5 CLI v3 has been deprecated! We highly recommend migrating to [**the latest version**](https://ui5.github.io/cli/stable/).
+
 ## Documentation
 UI5 Builder documentation can be found here: [ui5.github.io/cli](https://ui5.github.io/cli/v3/pages/Builder/)
 

azure-pipelines.yml

@@ -21,7 +21,7 @@ strategy:
       imageName: 'ubuntu-24.04'
       node_version: 18.x
     mac_node_lts_18:
-      imageName: 'macos-13'
+      imageName: 'macos-15'
       node_version: 18.x
     windows_node_lts_18:
       imageName: 'windows-2022'
@@ -30,7 +30,7 @@ strategy:
       imageName: 'ubuntu-24.04'
       node_version: 20.x
     mac_node_current:
-      imageName: 'macos-13'
+      imageName: 'macos-15'
       node_version: 20.x
     windows_node_current:
       imageName: 'windows-2022'