TOC update for 1.21.1 version

Author: VesaJuvonen

docs/toc.yml

@@ -474,7 +474,7 @@
     items:
     - name: Overview
       href: spfx/roadmap.md
-    - name: SPFx v1.21 - May 3, 2025
+    - name: SPFx v1.21.1 - May 3, 2025
       href: spfx/release-1.21.1.md
     - name: SPFx v1.21 - April 23, 2025
       href: spfx/release-1.21.md