Bump System.Text.Json from 10.0.2 to 10.0.3

---
updated-dependencies:
- dependency-name: System.Text.Json
  dependency-version: 10.0.3
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

dotnet/src/GitHub.Copilot.SDK.csproj

@@ -25,7 +25,7 @@
         <PackageReference Include="Microsoft.Extensions.AI.Abstractions" Version="10.2.0" />
         <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="10.0.2" />
         <PackageReference Include="StreamJsonRpc" Version="2.24.84" PrivateAssets="compile" />
-        <PackageReference Include="System.Text.Json" Version="10.0.2" />
+        <PackageReference Include="System.Text.Json" Version="10.0.3" />
     </ItemGroup>
 
     <!-- Generate version props file at build time (gitignored) -->