nixos/treewide: remove boolean examples for options

They contain no useful information and increase the length of the
autogenerated options documentation.

See discussion in #18816.

nixos/modules/programs/adb.nix

@@ -10,7 +10,6 @@ with lib;
     programs.adb = {
       enable = mkOption {
         default = false;
-        example = true;
         type = types.bool;
         description = ''
           Whether to configure system to use Android Debug Bridge (adb).

nixos/modules/programs/gphoto2.nix

@@ -10,7 +10,6 @@ with lib;
     programs.gphoto2 = {
       enable = mkOption {
         default = false;
-        example = true;
         type = types.bool;
         description = ''
           Whether to configure system to use gphoto2.

nixos/modules/programs/mosh.nix

@@ -14,7 +14,6 @@ in
         Whether to enable mosh. Note, this will open ports in your firewall!
       '';
       default = false;
-      example = true;
       type = lib.types.bool;
     };
   };

nixos/modules/programs/ssmtp.nix

@@ -22,7 +22,6 @@ in
       directDelivery = mkOption {
         type = types.bool;
         default = false;
-        example = true;
         description = ''
           Use the trivial Mail Transfer Agent (MTA)
           <command>ssmtp</command> package to allow programs to send
@@ -65,7 +64,6 @@ in
       useTLS = mkOption {
         type = types.bool;
         default = false;
-        example = true;
         description = ''
           Whether TLS should be used to connect to the default mail
           server.
@@ -75,7 +73,6 @@ in
       useSTARTTLS = mkOption {
         type = types.bool;
         default = false;
-        example = true;
         description = ''
           Whether the STARTTLS should be used to connect to the default
           mail server.  (This is needed for TLS-capable mail servers

nixos/modules/programs/tmux.nix

@@ -65,7 +65,6 @@ in {
 
       aggressiveResize = mkOption {
         default = false;
-        example = true;
         type = types.bool;
         description = ''
           Resize the window to the size of the smallest session for which it is the current window.
@@ -81,14 +80,12 @@ in {
 
       clock24 = mkOption {
         default = false;
-        example = true;
         type = types.bool;
         description = "Use 24 hour clock.";
       };
 
       customPaneNavigationAndResize = mkOption {
         default = false;
-        example = true;
         type = types.bool;
         description = "Override the hjkl and HJKL bindings for pane navigation and resizing in VI mode.";
       };
@@ -124,14 +121,12 @@ in {
 
       newSession = mkOption {
         default = false;
-        example = true;
         type = types.bool;
         description = "Automatically spawn a session if trying to attach and none are running.";
       };
 
       reverseSplit = mkOption {
         default = false;
-        example = true;
         type = types.bool;
         description = "Reverse the window split shortcuts.";
       };

nixos/modules/programs/vim.nix

@@ -9,7 +9,6 @@ in {
     defaultEditor = mkOption {
       type = types.bool;
       default = false;
-      example = true;
       description = ''
         When enabled, installs vim and configures vim to be the default editor
         using the EDITOR environment variable.