ci: enforce bash shell for windows matrix runner

Author: JohnnyWilson16

.github/workflows/ci-verification-gates.yml

@@ -20,6 +20,10 @@ env:
   PYTHONDONTWRITEBYTECODE: "1"
   PIP_DISABLE_PIP_VERSION_CHECK: "1"
 
+defaults:
+  run:
+    shell: bash
+
 jobs:
   guard-no-cov-bypass:
     name: Guard Against Coverage Bypasses
@@ -66,14 +70,14 @@ jobs:
           python -m pip install --upgrade pip
           python -m pip install -e .
           python -m pip install \
-            pytest>=8.0 \
-            pytest-cov>=5.0 \
-            hypothesis>=6.100 \
-            polars>=1.0 \
-            duckdb>=1.0 \
-            pyarrow>=15.0 \
-            scikit-learn>=1.4 \
-            psutil>=5.9
+            "pytest>=8.0" \
+            "pytest-cov>=5.0" \
+            "hypothesis>=6.100" \
+            "polars>=1.0" \
+            "duckdb>=1.0" \
+            "pyarrow>=15.0" \
+            "scikit-learn>=1.4" \
+            "psutil>=5.9"
 
       - name: Run unit, cross-engine schema, hostile object, streaming, and README claim gates
         run: |