doc: use correct dash in stability status

All other stability statuses use `-`, this one uses `–`. This commit
removes the inconsistency.

PR-URL: #55200
Reviewed-By: Moshe Atlow <[email protected]>
Reviewed-By: Richard Lau <[email protected]>
Reviewed-By: Debadree Chatterjee <[email protected]>

doc/api/fs.md

@@ -6630,7 +6630,7 @@ added:
   - v20.12.0
 -->
 
-> Stability: 1 – Experimental
+> Stability: 1 - Experimental
 
 * {string}