Fix DAE test failures by restoring scipy version constraint

The DAE project tests require scipy<1.15 due to numerical precision
requirements in the fully implicit index-2 DAE solver tests. Restoring
the original constraint that was inadvertently loosened during the
dependency update.

Fixes:
- test_RungeKuttaDAE.py::testOrderAccuracyFullyImplicitIndexTwo[TrapezoidalRuleDAE]
- test_problems.py::test_DiscontinuousTestDAE_SDC_detection[4]

Co-authored-by: pancetta <7158893+pancetta@users.noreply.github.com>

Author: Copilot

pySDC/projects/DAE/environment.yml

@@ -5,7 +5,7 @@ channels:
   - conda-forge
 dependencies:
   - numpy>=1.15.4,<3.0
-  - scipy>=0.17.1,<2.0
+  - scipy>=0.17.1,<1.15
   - dill>=0.2.6
   - mpich
   - mpi4py>=3.0.0,<4.0