Release Google.Cloud.AIPlatform.V1 version 3.9.0 (#13664)

Changes in this release:

### New features

- Add a dynamic retrieval API ([commit 39346c1](https://togithub.com/googleapis/google-cloud-dotnet/commit/39346c19aabf3069615026f5f668d04e41a370ca))
- Add continuous sync option in feature_view.proto ([commit de039c0](https://togithub.com/googleapis/google-cloud-dotnet/commit/de039c0d341ff01cae7af23cabf9759140795d60))
- Add psc_automation_configs to DeployIndex v1 ([commit 100ccd6](https://togithub.com/googleapis/google-cloud-dotnet/commit/100ccd6f0f9db723c786b231e931866f84536e23))

apis/Google.Cloud.AIPlatform.V1/Google.Cloud.AIPlatform.V1/Google.Cloud.AIPlatform.V1.csproj

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project Sdk="Microsoft.NET.Sdk">
   <PropertyGroup>
-    <Version>3.8.0</Version>
+    <Version>3.9.0</Version>
     <TargetFrameworks>netstandard2.0;net462</TargetFrameworks>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <Description>Recommended Google client library to access the AI Platform API (v1), which allows you to train high-quality custom machine learning models with minimal machine learning expertise and effort.</Description>

apis/Google.Cloud.AIPlatform.V1/docs/history.md

@@ -1,5 +1,13 @@
 # Version history
 
+## Version 3.9.0, released 2024-10-07
+
+### New features
+
+- Add a dynamic retrieval API ([commit 39346c1](https://github.com/googleapis/google-cloud-dotnet/commit/39346c19aabf3069615026f5f668d04e41a370ca))
+- Add continuous sync option in feature_view.proto ([commit de039c0](https://github.com/googleapis/google-cloud-dotnet/commit/de039c0d341ff01cae7af23cabf9759140795d60))
+- Add psc_automation_configs to DeployIndex v1 ([commit 100ccd6](https://github.com/googleapis/google-cloud-dotnet/commit/100ccd6f0f9db723c786b231e931866f84536e23))
+
 ## Version 3.8.0, released 2024-09-26
 
 ### New features

apis/apis.json

@@ -393,7 +393,7 @@
     },
     {
       "id": "Google.Cloud.AIPlatform.V1",
-      "version": "3.8.0",
+      "version": "3.9.0",
       "type": "grpc",
       "productName": "Cloud AI Platform",
       "productUrl": "https://cloud.google.com/ai-platform/docs/",