Fix macOS version typo in CHANGELOG

Author: eregon

CHANGELOG.md

@@ -58,7 +58,7 @@ Compatibility:
 * Allow `Fiber#raise` after `Fiber#transfer` like Ruby 3.0 (#2342).
 * Fix `ObjectSpace._id2ref` for Symbols and frozen String literals (#2358).
 * Implemented `Enumerator::Lazy#filter_map` (#2356).
-* Fix LLVM toolchain issue on macOS 10.13 (#2352, [oracle/graal#3383](https://github.com/oracle/graal/issues/3383)).
+* Fix LLVM toolchain issue on macOS 11.3 (#2352, [oracle/graal#3383](https://github.com/oracle/graal/issues/3383)).
 * Implement `IO#set_encoding_by_bom` (#2372, pawandubey).
 * Implemented `Enumerator::Lazy#with_index` (#2356).
 * Implement `rb_backref_set`.