refactor: IWYU updates

test/static/fractional_exponent_quantity.cpp

@@ -22,7 +22,7 @@
 
 #include <mp-units/compat_macros.h>
 #include <mp-units/framework.h>
-#include <mp-units/math.h>
+#include <mp-units/math.h>  // IWYU pragma: keep
 #include <mp-units/systems/isq/electromagnetism.h>
 #include <mp-units/systems/isq/si_quantities.h>
 #include <mp-units/systems/si/units.h>

test/static/international_test.cpp

@@ -20,7 +20,6 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 // SOFTWARE.
 
-#include <mp-units/math.h>
 #include <mp-units/systems/international.h>
 #include <mp-units/systems/isq/mechanics.h>
 #include <mp-units/systems/isq/space_and_time.h>

test/static/natural_test.cpp

@@ -20,9 +20,6 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 // SOFTWARE.
 
-#include <mp-units/math.h>
-#include <mp-units/systems/isq/mechanics.h>
-#include <mp-units/systems/isq/space_and_time.h>
 #include <mp-units/systems/natural.h>
 
 template<class T>

test/static/si_test.cpp

@@ -20,7 +20,6 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 // SOFTWARE.
 
-#include <mp-units/math.h>
 #include <mp-units/systems/si.h>
 #include <type_traits>