doc: fix typo in maintaining-zlib guide

PR-URL: nodejs#32292
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Rich Trott <rtrott@gmail.com>

doc/guides/maintaining-zlib.md

@@ -22,7 +22,7 @@ Check that Node.js still builds and tests.
 It may be necessary to update deps/zlib/zlib.gyp if any significant changes have
 occurred upstream.
 
-## Commiting zlib
+## Committing zlib
 
 Add zlib: `git add --all deps/zlib`