Increment package version after release of System.ClientModel (Azure#52758)

Author: azure-sdk

sdk/core/System.ClientModel/CHANGELOG.md

@@ -1,5 +1,15 @@
 # Release History
 
+## 1.8.0-beta.1 (Unreleased)
+
+### Features Added
+
+### Breaking Changes
+
+### Bugs Fixed
+
+### Other Changes
+
 ## 1.7.0 (2025-09-22)
 
 ### Features Added

sdk/core/System.ClientModel/src/System.ClientModel.csproj

@@ -2,9 +2,9 @@
 
   <PropertyGroup>
     <Description>Contains building blocks for clients that call cloud services.</Description>
-    <Version>1.7.0</Version>
+    <Version>1.8.0-beta.1</Version>
     <!--The ApiCompatVersion is managed automatically and should not generally be modified manually.-->
-    <ApiCompatVersion>1.6.1</ApiCompatVersion>
+    <ApiCompatVersion>1.7.0</ApiCompatVersion>
     <Nullable>enable</Nullable>
     <TargetFrameworks>netstandard2.0;net8.0;net9.0</TargetFrameworks>
     <PackageIcon>DotNetPackageIcon.png</PackageIcon>