Revert "fix: Enable runtime calls to mp_units::inverse() on Clang 18-20"

This reverts commit c78f31f.

Author: rothmichaels

src/core/include/mp-units/bits/hacks.h

@@ -122,7 +122,7 @@ MP_UNITS_DIAGNOSTIC_POP
 
 #endif
 
-#if defined MP_UNITS_COMP_CLANG && MP_UNITS_COMP_CLANG < 21
+#if defined MP_UNITS_COMP_CLANG && MP_UNITS_COMP_CLANG < 17
 
 #define MP_UNITS_CONSTEVAL constexpr
 

test/runtime/math_test.cpp

@@ -589,31 +589,4 @@ TEST_CASE("math operations", "[math]")
       REQUIRE_THAT(atan2(1. * isq::length[km], 1000. * isq::length[m]), AlmostEquals(45. * angle[deg]));
     }
   }
-
-  SECTION("inverse functions")
-  {
-    SECTION("inverse of time quantity returns frequency")
-    {
-      auto period = 2.0 * isq::time[s];
-      auto frequency = inverse<si::hertz>(period);
-      REQUIRE(frequency == 0.5 * isq::frequency[Hz]);
-    }
-
-    SECTION("inverse works with runtime values")
-    {
-      // Test the specific case that fails with consteval
-      double runtime_value = 3.0;
-      auto period = runtime_value * isq::time[s];
-      auto frequency = inverse<si::hertz>(period);
-      auto expected = (1.0/3.0) * isq::frequency[Hz];
-      REQUIRE_THAT(frequency, AlmostEquals(expected));
-    }
-
-    SECTION("inverse with different input units")
-    {
-      auto period_ms = 500.0 * isq::time[ms];
-      auto frequency = inverse<si::hertz>(period_ms);
-      REQUIRE(frequency == 2.0 * isq::frequency[Hz]);
-    }
-  }
 }