Describe the bug

If the version field is required, the placeholder of '1.0.0' shall be removed.

If the version field is NOT required, the corresponding validation logic shall be removed.

Expected behavior

1. The version field of MCP Server can be left empty when creating.
2. After the validation error is corrected, the new MCP server can be created.

Actually behavior

1. The version field of MCP Server cannot be left empty when creating.
2. After the validation error is corrected, nothing happens when clicking the "Publish" button again.

How to Reproduce
Steps to reproduce the behavior:

1. Go to 'MCP Management' -> 'MCP List'
2. Click on 'Create MCP Server' button
3. Fill all necessary fields except 'Service Version'
4. Click on 'Publish' button.
5. A validation error pops up saying 'version is required'
   
6. Put '1.0.0' in Service Version
7. Click on 'Publish' button.
8. Nothing happens.

Desktop (please complete the following information):

• OS: Windows 10
• Version nacos-server 3.0.1

Additional context
Add any other context about the problem here.