fix some warnings with newer rust

The warning is that some of the variants are never read.
In the case of ftwrap, they are referenced via ffi.
For the other locations, we want them for debug purposes.

wezterm-font/src/ftwrap.rs

@@ -1294,6 +1294,7 @@ struct FreeTypeStream {
     name: String,
 }
 
+#[allow(dead_code)]
 enum StreamBacking {
     File(BufReader<File>),
     Map(Mmap),

wezterm-mux-server/src/daemonize.rs

@@ -5,6 +5,7 @@ use std::io::Write;
 use std::os::unix::io::{AsRawFd, IntoRawFd, RawFd};
 
 enum Fork {
+    #[allow(dead_code)]
     Child(pid_t),
     Parent(pid_t),
 }

wezterm-toast-notification/src/dbus.rs

@@ -71,6 +71,7 @@ enum Reason {
     Expired,
     Dismissed,
     Closed,
+    #[allow(dead_code)]
     Unknown(u32),
 }
 

wezterm/src/asciicast.rs

@@ -626,6 +626,7 @@ impl PlayCommand {
     }
 }
 
+#[allow(dead_code)]
 #[derive(Debug)]
 enum Summarized {
     Action(Action),