Make -v|--version opt-in

We added an automatic version option in 0.49. We did this with good
intentions, but forgot that people might already use --version
as an option for a root command.

This commit makes -v|--version completely opt-in.

test/Spectre.Console.Cli.Tests/Expectations/Help/Root_Examples_Leafs_None.Output.verified.txt

@@ -1,9 +1,8 @@
-USAGE:
+USAGE:
     myapp [OPTIONS] <COMMAND>
 
 OPTIONS:
-    -h, --help       Prints help information
-    -v, --version    Prints version information
+    -h, --help    Prints help information
 
 COMMANDS:
     animal    The animal command