Replace all occurrences of 's1-prod-macos-13-5-arm64' with 's1-macos-15-arm64-8'

Author: service-bot-app[bot]

.semaphore/post_install.yml

@@ -151,7 +151,7 @@ blocks:
     task:
       agent:
         machine:
-          type: s1-prod-macos-13-5-arm64
+          type: s1-macos-15-arm64-8
       jobs:
         - name: "Install"
           matrix:

.semaphore/semaphore.yml

@@ -79,7 +79,7 @@ blocks:
     task:
       agent:
         machine:
-          type: s1-prod-macos-13-5-arm64
+          type: s1-macos-15-arm64-8
       jobs:
         - name: 'Build from source and test'
           commands:
@@ -336,7 +336,7 @@ blocks:
     task:
       agent:
         machine:
-          type: s1-prod-macos-13-5-arm64
+          type: s1-macos-15-arm64-8
       env_vars:
         - name: ARCHITECTURE
           value: "arm64"