update changeset. Use empty string instead of none

Author: swcollard

.changesets/feat_trace_session_id.md

@@ -1,3 +1,3 @@
-### feat: Add mcp-session-id header to HTTP request trace attributes
+### feat: Add mcp-session-id header to HTTP request trace attributes - @swcollard PR #421
 
 Includes the value of the [Mcp-Session-Id](https://modelcontextprotocol.io/specification/2025-06-18/basic/transports#session-management) HTTP header as an attribute of the trace for HTTP requests to the MCP Server

crates/apollo-mcp-server/src/server/states/starting.rs

@@ -222,7 +222,7 @@ impl Starting {
                                 "mcp_server",
                                 method = %request.method(),
                                 uri = %request.uri(),
-                                session_id = %request.headers().get("mcp-session-id").and_then(|v| v.to_str().ok()).unwrap_or("none"),
+                                session_id = %request.headers().get("mcp-session-id").and_then(|v| v.to_str().ok()).unwrap_or(""),
                                 status_code = tracing::field::Empty,
                             )
                         })