correct std version

server/lake-manifest.json

@@ -4,10 +4,10 @@
  [{"url": "https://github.com/leanprover/std4.git",
    "type": "git",
    "subDir": null,
-   "rev": "bf8a6ea960d5a99f8e30cbf5597ab05cd233eadf",
+   "rev": "a652e09bd81bcb43ea132d64ecc16580b0c7fa50",
    "name": "std",
    "manifestFile": "lake-manifest.json",
-   "inputRev": null,
+   "inputRev": "v4.3.0-rc2",
    "inherited": false,
    "configFile": "lakefile.lean"}],
  "name": "GameServer",

server/lakefile.lean

@@ -3,7 +3,10 @@ open Lake DSL
 
 package GameServer
 
-require std from git "https://github.com/leanprover/std4.git"
+-- Using this assumes that each dependency has a tag of the form `v4.X.0`.
+def leanVersion : String := s!"v{Lean.versionString}"
+
+require std from git "https://github.com/leanprover/std4.git" @ leanVersion
 
 lean_lib GameServer