fixup! Nix: update rust versions

nix/rust.nix

@@ -8,19 +8,16 @@ let
       # override stdenv.targetPlatform here, if neccesary
     };
   toolchainHashes = {
-    "1.71.0" = "sha256-ks0nMEGGXKrHnfv4Fku+vhQ7gx76ruv6Ij4fKZR3l78=";
-    "1.72.0" = "sha256-Q9UgzzvxLi4x9aWUJTn+/5EXekC98ODRU1TwhUs9RnY=";
+    "1.71" = "sha256-R0F0Risbr74xg9mEYydyebx/z0Wu6HI0/KWwrV30vZo=";
+    "1.72" = "sha256-dxE7lmCFWlq0nl/wKcmYvpP9zqQbBitAQgZ1zx9Ooik=";
     # copy the placeholder line with the correct toolchain name when adding a new toolchain
     # That is,
-    # 1. Put the correct verions name;
+    # 1. Put the correct version name;
     #
-    # 2. Put anything, say "sha256-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA= as the hash.
-    #    You'll get an error:
+    # 2. Put the hash you get in line "got" from the error you obtain, which looks like
     #    error: hash mismatch in fixed-output derivation '/nix/store/XXXXX'
     #          specified: sha256-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
     #             got:    sha256-Q9UgzzvxLi4x9aWUJTn+/5EXekC98ODRU1TwhUs9RnY=
-    #
-    # 3. Now put put the hash from got instead of the one you specified in 2.
     "placeholder" = "sha256-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=";
   };
   # rust-toolchain.toml -> { rustc, cargo, rust-analyzer, ... }