update schema url point to the actual location (#884)

<!-- Provide a brief summary of your changes -->

## Motivation and Context
This PR ensures that the draft URL points to the actual draft schema 
improvement suggested in
https://github.com/modelcontextprotocol/registry/issues/814


## How Has This Been Tested?
<!-- Have you tested this in a real application? Which scenarios were
tested? -->

## Breaking Changes
<!-- Will users need to update their code or configurations? -->

## Types of changes
<!-- What types of changes does your code introduce? Put an `x` in all
the boxes that apply: -->
- [x] Bug fix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing
functionality to change)
- [ ] Documentation update

## Checklist
<!-- Go over all the following points, and put an `x` in all the boxes
that apply. -->
- [ ] I have read the [MCP
Documentation](https://modelcontextprotocol.io)
- [ ] My code follows the repository's style guidelines
- [ ] New and existing tests pass locally
- [ ] I have added appropriate error handling
- [ ] I have added or updated documentation as needed

## Additional context
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-->

tools/extract-server-schema/main.go

@@ -13,7 +13,7 @@ import (
 
 const (
 	openAPIPath     = "docs/reference/api/openapi.yaml"
-	schemaOutputDir = "docs/reference/server-json"
+	schemaOutputDir = "docs/reference/server-json/draft"
 )
 
 func main() {
@@ -93,7 +93,7 @@ func main() {
 	// When releasing, the schema is published to a versioned URL (e.g., 2025-10-17)
 	// on https://github.com/modelcontextprotocol/static
 	_ = version // version from OpenAPI spec available if needed
-	schemaID := "https://static.modelcontextprotocol.io/schemas/draft/server.schema.json"
+	schemaID := "https://raw.githubusercontent.com/modelcontextprotocol/registry/main/docs/reference/server-json/draft/server.schema.json"
 	jsonSchema := map[string]interface{}{
 		"$comment":    "This file is auto-generated from docs/reference/api/openapi.yaml. Do not edit manually. Run 'make generate-schema' to update.",
 		"$schema":     "http://json-schema.org/draft-07/schema#",