Add isArchived: true to retired Phi-3 and Phi-3.5 models (#5103)

All 8 models have InferenceRetirementDate of 2025-08-30 (already past).
Adding isArchived: true for consistency with other retired models.

Author: amibp

assets/models/system/phi-3-medium-128k-instruct/spec.yaml

@@ -1,6 +1,7 @@
 $schema: https://azuremlschemas.azureedge.net/latest/model.schema.json
 name: Phi-3-medium-128k-instruct
 path: ./
+isArchived: true
 properties:
   SharedComputeCapacityEnabled: "True"
   languages: en

assets/models/system/phi-3-medium-4k-instruct/spec.yaml

@@ -1,6 +1,7 @@
 $schema: https://azuremlschemas.azureedge.net/latest/model.schema.json
 name: Phi-3-medium-4k-instruct
 path: ./
+isArchived: true
 properties:
   SharedComputeCapacityEnabled: "True"
   languages: en

assets/models/system/phi-3-mini-128k-instruct/spec.yaml

@@ -1,6 +1,7 @@
 $schema: https://azuremlschemas.azureedge.net/latest/model.schema.json
 name: Phi-3-mini-128k-instruct
 path: ./
+isArchived: true
 properties:
   SharedComputeCapacityEnabled: "True"
   languages: en

assets/models/system/phi-3-mini-4k-instruct/spec.yaml

@@ -1,6 +1,7 @@
 $schema: https://azuremlschemas.azureedge.net/latest/model.schema.json
 name: Phi-3-mini-4k-instruct
 path: ./
+isArchived: true
 properties:
   SharedComputeCapacityEnabled: "True"
   languages: en

assets/models/system/phi-3-small-128k-instruct/spec.yaml

@@ -1,6 +1,7 @@
 $schema: https://azuremlschemas.azureedge.net/latest/model.schema.json
 name: Phi-3-small-128k-instruct
 path: ./
+isArchived: true
 properties:
   SharedComputeCapacityEnabled: "True"
   languages: en

assets/models/system/phi-3.5-mini-128k-instruct/spec.yaml

@@ -1,6 +1,7 @@
 $schema: https://azuremlschemas.azureedge.net/latest/model.schema.json
 name: Phi-3.5-mini-instruct
 path: ./
+isArchived: true
 properties:
   SharedComputeCapacityEnabled: "True"
   languages: en

assets/models/system/phi-3.5-moe-128k-instruct/spec.yaml

@@ -1,6 +1,7 @@
 $schema: https://azuremlschemas.azureedge.net/latest/model.schema.json
 name: Phi-3.5-MoE-instruct
 path: ./
+isArchived: true
 properties:
   SharedComputeCapacityEnabled: "True"
   languages: en

assets/models/system/phi-3.5-vision-128k-instruct/spec.yaml

@@ -1,6 +1,7 @@
 $schema: https://azuremlschemas.azureedge.net/latest/model.schema.json
 name: Phi-3.5-vision-instruct
 path: ./
+isArchived: true
 properties:
   SharedComputeCapacityEnabled: "True"
   languages: en