seq:floatparse:add license header

Issue uutils#6935

src/uu/seq/src/floatparse.rs

@@ -1,3 +1,7 @@
+// This file is part of the uutils coreutils package.
+//
+// For the full copyright and license information, please view the LICENSE
+// file that was distributed with this source code.
 use crate::extendedbigdecimal::ExtendedBigDecimal;
 use crate::number::PreciseNumber;
 use crate::numberparse::ParseNumberError;