doc: remove quotes from pr-url metadata

Author: haramj

doc/api/http.md

@@ -118,7 +118,7 @@ added: v0.3.4
 changes:
  - version:
  - REPLACEME
- pr-url: "https://github.com/nodejs/node/pull/59315"
+ pr-url: https://github.com/nodejs/node/pull/59315
  description: Add support for `agentKeepAliveTimeoutBuffer`.
  - version:
  - v24.5.0