refactoring: arcSine function test, rename

src/test/test_funktionen.c

@@ -155,7 +155,7 @@ void test_tangent_for_1_5(void) {
     // Add more test cases for different inputs and expected outputs
 }
 
-void test_arcSine(void) {
+void test_arcSine_for_0_5(void) {
     float result = arcSine(0.5);
     TEST_ASSERT_EQUAL_FLOAT(0.523599, result);
     // Add more test cases for different inputs and expected outputs