Add kaya-session package for server-side HTTP session management

requirements-dev.txt

@@ -83,8 +83,11 @@ file:./packages/kaya-core
     # via
     #   -r requirements-dev.in
     #   kaya-rsgi
+    #   kaya-session
 file:./packages/kaya-rsgi
     # via -r requirements-dev.in
+file:./packages/kaya-session
+    # via -r requirements-dev.in
 keyring==25.7.0
     # via twine
 librt==0.13.0