Update UnbrandedGeneratorVersion to 1.0.0-alpha.20250617.1 (Azure#50661)

Co-authored-by: Ubuntu <cloudtest@37495274c000004.tkkhlgj2u51eln3mcb0lygmbye.dx.internal.cloudapp.net>

Author: azure-sdk

eng/Packages.Data.props

@@ -450,7 +450,7 @@
 
   <PropertyGroup>
     <TestProxyVersion>1.0.0-dev.20250501.1</TestProxyVersion>
-    <UnbrandedGeneratorVersion>1.0.0-alpha.20250613.2</UnbrandedGeneratorVersion>
+    <UnbrandedGeneratorVersion>1.0.0-alpha.20250617.1</UnbrandedGeneratorVersion>
     <AzureGeneratorVersion>1.0.0-alpha.20250527.2</AzureGeneratorVersion>
   </PropertyGroup>
 </Project>

eng/packages/http-client-csharp/generator/TestProjects/Local/Basic-TypeSpec/src/Generated/BasicTypeSpecClient.cs

@@ -38,7 +38,7 @@
     "dist/generator/**"
   ],
   "dependencies": {
-    "@typespec/http-client-csharp": "1.0.0-alpha.20250611.5"
+    "@typespec/http-client-csharp": "1.0.0-alpha.20250617.1"
   },
   "devDependencies": {
     "@azure-tools/azure-http-specs": "0.1.0-alpha.17",