This method has no generic usages, it does not need to be generic

cc @paperdave

src/string_mutable.zig

@@ -37,7 +37,7 @@ pub const MutableString = struct {
     }
 
     pub fn owns(this: *const MutableString, slice: []const u8) bool {
-        return bun.isSliceInBuffer(u8, slice, this.list.items.ptr[0..this.list.capacity]);
+        return bun.isSliceInBuffer(slice, this.list.items.ptr[0..this.list.capacity]);
     }
 
     pub fn growIfNeeded(self: *MutableString, amount: usize) !void {