[libc++][NFC] Fix license comment typo

Fixes #72024

Author: ldionne

libcxx/include/__algorithm/ranges_equal_range.h

@@ -1,6 +1,6 @@
 //===----------------------------------------------------------------------===//
 //
-// Part of the LLVM __project, under the Apache License v2.0 with LLVM Exceptions.
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //