Pin IntegrationTest to mf/subdir-inputs too

The IntegrationTest reusable on this branch adds substantive-only
default behavior, subdir, and exclude-subdirs. Pinning here so the
smoke test actually exercises that path (was still on the v2
release tag before this commit).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: mtfishman

.github/workflows/IntegrationTest.yml

@@ -17,7 +17,7 @@ permissions:
 jobs:
   integration-test:
     name: "IntegrationTest"
-    uses: "ITensor/ITensorActions/.github/workflows/IntegrationTest.yml@v2"
+    uses: "ITensor/ITensorActions/.github/workflows/IntegrationTest.yml@mf/subdir-inputs"
     secrets: "inherit"
     with:
       localregistry: "https://github.com/ITensor/ITensorRegistry.git"