fix: unwatch cannot error

src/nightwatch.zig

@@ -72,7 +72,7 @@ pub fn watch(self: *@This(), path: []const u8) Error!void {
 }
 
 /// Stop watching a previously watched path
-pub fn unwatch(self: *@This(), path: []const u8) Error!void {
+pub fn unwatch(self: *@This(), path: []const u8) void {
     self.backend.remove_watch(self.allocator, path);
 }
 

src/nightwatch_test.zig

@@ -393,7 +393,7 @@ test "unwatch stops delivering events for that directory" {
     try std.testing.expect(th.hasChange(file1, .created));
 
     // Stop watching, then create another file - must NOT appear.
-    try watcher.unwatch(tmp);
+    watcher.unwatch(tmp);
     const count_before = th.events.items.len;
 
     const file2 = try std.fmt.allocPrint(allocator, "{s}/after_unwatch.txt", .{tmp});