[#1392] Remove quaternion diffusion runtime size check

Drop the QuaternionStateData propagation-time diffusion shape guard so it
matches the regular StateData convention of trusting configured diffusion
storage. Remove the unit test that only covered that runtime resize check.

Author: schaubh

src/simulation/dynamics/_GeneralModuleFiles/quaternionStateData.cpp

@@ -141,14 +141,6 @@ QuaternionStateData::propagateState(double dt, std::vector<double> pseudoStep)
 
     for (size_t i = 0; i < getNumNoiseSources(); i++) {
         const auto& diffusion = this->stateDiffusion.at(i);
-        if (diffusion.rows() != 3 || diffusion.cols() != 1) {
-            auto errorMsg = "State " + this->getName() + " has a quaternion diffusion with size " +
-                            std::to_string(diffusion.rows()) + "x" +
-                            std::to_string(diffusion.cols()) + ". QuaternionStateData expects " +
-                            "each diffusion source to be a 3x1 rotational increment vector.";
-            logAndThrow(this->bskLogger, errorMsg);
-        }
-
         Eigen::Vector3d stochasticRotVec(diffusion(0), diffusion(1), diffusion(2));
         q = applyRotationVector(q, stochasticRotVec * pseudoStep.at(i));
     }

src/simulation/dynamics/tests/test_quaternionStateData.cpp

@@ -198,14 +198,6 @@ TEST(QuaternionStateDataTest, RejectsMismatchedPseudoStepCount)
     EXPECT_THROW(q.propagateState(0.0, {1.0, 2.0}), BasiliskError);
 }
 
-TEST(QuaternionStateDataTest, RejectsNonRotationalDiffusionSize)
-{
-    auto q = makeQ(1.0, 0.0, 0.0, 0.0);
-    q.setNumNoiseSources(1);
-
-    EXPECT_THROW(q.propagateState(0.0, {1.0}), BasiliskError);
-}
-
 TEST(QuaternionStateDataTest, CloneDeepCopiesAndIsIndependent)
 {
     auto q = makeQ(0.5, 0.5, 0.5, 0.5, /*omega*/ 0.1, 0.2, 0.3);