.NET: `azd deploy` fails: .csproj targets net10.0 but Dockerfile uses SDK 9.0 for `HostedAgents` samples

[Menghua1]

Description:
During azd deploy for AgentWithHostedMCP, AgentWithTextSearchRag, AgentsInWorkflows, the Docker build fails with the following error:

Steps to Reproduce:

1. Initialize the project: azd init --template Azure-Samples/ai-foundry-starter-basic.
2. Initialize AI agent: azd ai agent init -m https://github.com/microsoft/agent-framework/blob/main/dotnet/samples/HostedAgents/AgentWithHostedMCP/agent.yaml
3. Run azd up.

Environment:

• Azd version: azd version 1.22.0-beta.1-daily.5607396 (commit 42e1af10cb82de9542055e5662d69eb79bae37d9)
• AI Agent Extension version: 0.1.2-preview
• Agent: AgentWithHostedMCP, AgentWithTextSearchRag, AgentsInWorkflows
• OS: Windows

Expected Behavior:
The azd deploy command runs successfully.

@JeffreyCA and @rajeshkamal5050 for notification.