Update casts for latest Zig (#19)

* `@enumToInt` => `@intFromEnum`

The `@enumToInt` built-in was just renamed to `@intFromEnum`.

ref: ziglang/zig@a6c8ee5

* `@bitCast` no longer needs the type parameter

`@bitCast` and other casts no longer need
the destination type as an argument.

ref: ziglang/zig#16163

src/cursor.zig

@@ -14,7 +14,7 @@ pub const CursorMode = enum(u8) {
 };
 
 pub fn setCursorMode(writer: anytype, mode: CursorMode) !void {
-    const modeNumber = @enumToInt(mode);
+    const modeNumber = @intFromEnum(mode);
     try writer.print(csi ++ "{d} q", .{modeNumber});
 }
 

src/style.zig

@@ -96,11 +96,11 @@ pub const FontStyle = packed struct {
     };
 
     pub fn toU11(self: Self) u11 {
-        return @bitCast(u11, self);
+        return @bitCast(self);
     }
 
     pub fn fromU11(bits: u11) Self {
-        return @bitCast(Self, bits);
+        return @bitCast(bits);
     }
 
     /// Returns true iff this font style contains no attributes