ci/vmtest: denylist tc_edt on s390x

Still flaky [1]:
- https://github.com/kernel-patches/bpf/actions/runs/20625136600/job/59234704420
- https://github.com/kernel-patches/bpf/actions/runs/20625127042/job/59234610351

[1] d911608

Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev>

Author: theihor

ci/vmtest/configs/DENYLIST.s390x

@@ -1,3 +1,4 @@
 arena_spin_lock
 map_kptr/success-map
 res_spin_lock_stress
+tc_edt