Upgrade JS REX Validation Tool (#29229)

This PR upgrades the JS REX Validation Tool to the latest version. Testing was done in https://dev.azure.com/azure-sdk/internal/_build/results?buildId=3677655
2024-04-12 09:20:46 -07:00 · 2024-04-12 09:20:46 -07:00 · ceaf03a8ce
--- a/eng/scripts/docs/type2docfx.version.txt
+++ b/eng/scripts/docs/type2docfx.version.txt
@ -1 +1 @@
-2.0.8
+2.1.0
 @ -1 +1 @@
 .0.8
 .1.0