doc: fix typo in assert.md

PR-URL: #34316
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

doc/api/assert.md

@@ -18,7 +18,7 @@ changes:
       - v12.16.2
     description: Changed "strict mode" to "strict assertion mode" and "legacy
                  mode" to "legacy assertion mode" to avoid confusion with the
-                 more usual meaining of "strict mode".
+                 more usual meaning of "strict mode".
   - version: v9.9.0
     pr-url: https://github.com/nodejs/node/pull/17615
     description: Added error diffs to the strict assertion mode.