Increment version after release (#1020)

* Increment package version after release

* Update CHANGELOG.md

---------

Co-authored-by: Arthur Ma <mars.arthur@263.net>

Author: azure-sdk

CHANGELOG.md

@@ -2,6 +2,16 @@
 
 The Azure MCP Server updates automatically by default whenever a new release comes out 🚀. We ship updates twice a week on Tuesdays and Thursdays 😊
 
+## 0.5.8 (Unreleased)
+
+### Features Added
+
+### Breaking Changes
+
+### Bugs Fixed
+
+### Other Changes
+
 ## 0.5.7 (2025-08-19)
 
 ### Features Added

Directory.Build.props

@@ -1,6 +1,6 @@
 <Project>
   <PropertyGroup>
-    <Version>0.5.7</Version>
+    <Version>0.5.8</Version>
     <TargetFramework>net9.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>