Enable blending in PenLayer test

Author: adazem009

test/penlayer/penlayer_test.cpp

@@ -30,6 +30,11 @@ class PenLayerTest : public testing::Test
             m_surface.create();
             Q_ASSERT(m_surface.isValid());
             m_context.makeCurrent(&m_surface);
+
+            QOpenGLFunctions glF(&m_context);
+            glF.initializeOpenGLFunctions();
+            glF.glEnable(GL_BLEND);
+            glF.glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
         }
 
         void TearDown() override