fix: restore Python 3.10 release gate

Author: gawcista

.github/workflows/release-gate.yml

@@ -14,8 +14,8 @@ jobs:
         # Declared minimum and one current Python supported by the project.
         python-version: ["3.10", "3.13"]
     steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-python@v5
+      - uses: actions/checkout@v5
+      - uses: actions/setup-python@v6
         with:
           python-version: ${{ matrix.python-version }}
       - name: Install package and test extras
@@ -28,8 +28,8 @@ jobs:
     runs-on: ubuntu-latest
     needs: source-suite
     steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-python@v5
+      - uses: actions/checkout@v5
+      - uses: actions/setup-python@v6
         with:
           python-version: "3.13"
       - name: Install build frontend

valleyscope/analysis/standard_setting_kmap.py

@@ -2886,10 +2886,13 @@ def _reconstruct_subgroup_standard_cell(
 
     if vf.get("status") != "passed":
         result["status"] = "rejected"
+        verification_reason = vf.get(
+            "reason",
+            "transformed parent rotations do not match standard-setting rotations",
+        )
         result["reason"] = (
             "operation-basis verification failed: "
-            f"{vf.get('reason', 'transformed parent rotations do not '
-                       'match standard-setting rotations')}"
+            f"{verification_reason}"
         )
         return result