chore(http): create constant for session id header#246

chr-hertel merged 1 commit intomodelcontextprotocol:mainmodelcontextprotocol/php-sdk:mainfrom

EdouardCourty:chore/create-constant-for-session-id-headerEdouardCourty/php-sdk:chore/create-constant-for-session-id-headerCopy head branch name to clipboard