Testnet reset dates updated (#2292)

* Testnet reset dates updated

* Update docs/networks/README.mdx

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: carstenjacobsen

docs/networks/README.mdx

@@ -59,13 +59,11 @@ Testnet and Futurenet are reset periodically to the genesis ledger to declutter
 
 Futurenet resets are on a less regular cadence than Testnet resets and don't have a set schedule.
 
-Testnet resets typically happen once per quarter at 17:00 UTC and are announced at least two weeks in advance on the [Stellar Dashboard](http://dashboard.stellar.org/) and through several developer community channels.
+Testnet resets typically happen 2-4 times per year at 17:00 UTC and are announced at least two weeks in advance on the [Stellar Dashboard](https://dashboard.stellar.org/) and through several developer community channels.
 
 Here are the scheduled 2026 dates:
 
-- March 18, 2026
 - June 17, 2026
-- September 16, 2026
 - December 16, 2026
 
 If you run a Testnet or Futurenet Horizon instance, you need to re-join and re-sync to the network after a reset. Check out how to do that here: [Testnet Reset](https://github.com/stellar/packages/blob/master/docs/testnet-reset.md).