fix: add missing spec_path column to LiteLLM_MCPServerTable schema (#22820)

The OpenAPI-to-MCP feature (PR #21575) added spec_path to the code
(_types.py, mcp_server_manager.py) but missed adding the column to
the Prisma schema files. This causes "Could not find field spec_path"
errors when creating OpenAPI-based MCP servers via the UI or API.

Adds `spec_path String?` to LiteLLM_MCPServerTable in all three
schema files (root, litellm/proxy, litellm-proxy-extras).

Made-with: Cursor

litellm-proxy-extras/litellm_proxy_extras/schema.prisma

@@ -277,6 +277,7 @@ model LiteLLM_MCPServerTable {
   alias        String?
   description  String?
   url          String?
+  spec_path    String?
   transport    String         @default("sse")
   auth_type    String?        
   credentials  Json?          @default("{}")

litellm/proxy/schema.prisma

@@ -277,6 +277,7 @@ model LiteLLM_MCPServerTable {
   alias        String?
   description  String?
   url          String?
+  spec_path    String?
   transport    String         @default("sse")
   auth_type    String?        
   credentials  Json?          @default("{}")

schema.prisma

@@ -277,6 +277,7 @@ model LiteLLM_MCPServerTable {
   alias        String?
   description  String?
   url          String?
+  spec_path    String?
   transport    String         @default("sse")
   auth_type    String?        
   credentials  Json?          @default("{}")