Remove references to android14-6.1-pkvm_experimental

Bug: 352009226
Test: presubmit
Change-Id: I491c187a6aa919344a5e512bb3e96e6f181f11f9
diff --git a/apex/sign_virt_apex.py b/apex/sign_virt_apex.py
index 1a59894..4a19c3d 100644
--- a/apex/sign_virt_apex.py
+++ b/apex/sign_virt_apex.py
@@ -498,7 +498,7 @@
     RunCommand(args, cmd)
 
 
-gki_versions = ['android14-6.1-pkvm_experimental', 'android15-6.6']
+gki_versions = ['android15-6.6']
 
 # dict of (key, file) for re-sign/verification. keys are un-versioned for readability.
 virt_apex_non_gki_files = {