Revert "boards: mps3_corstone300_fvp_ns: disable twister"

What is changed?
 - This reverts commit 1c596b8b77.

Why is this change needed?
 - This commit was added as a temporary fix for #81656.
   Since the previous commit (part of #83360) fixes the issue,
   we don't need this anymore.

Signed-off-by: Sudan Landge <sudan.landge@arm.com>

boards/arm/mps3/mps3_corstone300_fvp_ns.yaml

@@ -7,8 +7,6 @@ type: mcu
 arch: arm
 ram: 2048
 flash: 512
-# Related issue #81656
-twister: false
 toolchain:
   - gnuarmemb
   - zephyr