Stop recommending bcrypt everywhere

By passing no method to mkpasswd we make it select the strongest cipher
that libxcrypt recommends.

Replaces the example hashes with yescrypt hashes, which is the current
default.

default.nix

@@ -152,12 +152,12 @@ in
               hashedPassword = mkOption {
                 type = with types; nullOr str;
                 default = null;
-                example = "$6$evQJs5CFQyPAW09S$Cn99Y8.QjZ2IBnSu4qf1vBxDRWkaIZWOtmu1Ddsm3.H3CFpeVc0JU4llIq8HQXgeatvYhh5O33eWG3TSpjzu6/";
+                example = "$y$j9T$vfGrwkAaXCjCEWtVNMQck1$383uIXQmn2z0hnmVAA8kwFQmjNj78.nYbvWeyNLIaP1";
                 description = ''
                   The user's hashed password. Use `mkpasswd` as follows
 
                   ```
-                  nix-shell -p mkpasswd --run 'mkpasswd -sm bcrypt'
+                  nix-shell -p mkpasswd --run 'mkpasswd -s'
                   ```
 
                   Warning: this is stored in plaintext in the Nix store!
@@ -173,7 +173,7 @@ in
                   A file containing the user's hashed password. Use `mkpasswd` as follows
 
                   ```
-                  nix-shell -p mkpasswd --run 'mkpasswd -sm bcrypt'
+                  nix-shell -p mkpasswd --run 'mkpasswd -s'
                   ```
                 '';
               };
@@ -275,10 +275,10 @@ in
       );
       example = {
         user1 = {
-          hashedPassword = "$6$evQJs5CFQyPAW09S$Cn99Y8.QjZ2IBnSu4qf1vBxDRWkaIZWOtmu1Ddsm3.H3CFpeVc0JU4llIq8HQXgeatvYhh5O33eWG3TSpjzu6/";
+          hashedPassword = "$y$j9T$y6eZ1o.IvVNfdGMAsUEvh1$6K/llP52uw2iDh4iSwtAn54/JYy7FzCcoCHmjmx00H5";
         };
         user2 = {
-          hashedPassword = "$6$oE0ZNv2n7Vk9gOf$9xcZWCCLGdMflIfuA0vR1Q1Xblw6RZqPrP94mEit2/81/7AKj2bqUai5yPyWE.QYPyv6wLMHZvjw3Rlg7yTCD/";
+          hashedPassword = "$y$j9T$hZ.ubq0M897Hw.znxnGG9.$14EJBoOwbwKeWt.W4vpnBPEBZC9mYz4fWI9kOCLoZf4";
         };
       };
       description = ''
@@ -287,7 +287,7 @@ in
         follows
 
         ```
-        nix-shell -p mkpasswd --run 'mkpasswd -sm bcrypt'
+        nix-shell -p mkpasswd --run 'mkpasswd -s'
         ```
       '';
       default = { };

docs/setup-example.nix

@@ -32,7 +32,7 @@
     x509.useACMEHost = config.mailserver.fqdn;
 
     # A list of all login accounts. To create the password hashes, use
-    # nix-shell -p mkpasswd --run 'mkpasswd -sm bcrypt'
+    # nix-shell -p mkpasswd --run 'mkpasswd -s'
     loginAccounts = {
       "user1@example.com" = {
         hashedPasswordFile = "/a/file/containing/a/hashed/password";

tests/internal.nix

@@ -38,7 +38,7 @@ let
         inherit password;
       }
       ''
-        mkpasswd -sm bcrypt <<<"$password" > $out
+        mkpasswd -s <<<"$password" > $out
       '';
 
   hashedPasswordFile = hashPassword "my-password";

tests/multiple.nix

@@ -15,7 +15,7 @@ let
         inherit password;
       }
       ''
-        mkpasswd -sm bcrypt <<<"$password" > $out
+        mkpasswd -s <<<"$password" > $out
       '';
 
   password = pkgs.writeText "password" "password";