add separate pr workflow to call xtest wf

Author: elizabethhealy

.github/workflows/xtest.yml

@@ -1,6 +1,5 @@
 name: X-Test
 on:
-  pull_request:
   workflow_call:
     inputs:
       platform-ref:

.github/workflows/xtest_pr.yml

@@ -0,0 +1,13 @@
+name: Run X-Test
+on:
+  pull_request:
+
+jobs:
+  platform-xtest:
+    permissions:
+      contents: read
+      packages: read
+    needs: platform-integration
+    uses: opentdf/tests/.github/workflows/xtest.yml@{{ github.ref }}
+    with:
+      tests-ref: ${{ github.ref }}