Delete problematic constexpr variable

This triggers bugs in String and other classes regarding
constexpr-compatibility of constructors and destructors.  It does not
appear to be tested correctly in CI.

Works around DISTRHO#440.

distrho/DistrhoDetails.hpp

@@ -743,16 +743,6 @@ struct Parameter {
     }
 };
 
-#if __cplusplus >= 202001L /* TODO */
-/**
-   Bypass parameter definition in constexpr form.
- */
-static constexpr const Parameter kParameterBypass = {
-    kParameterIsAutomatable|kParameterIsBoolean|kParameterIsInteger,
-    "Bypass", "Bypass", "dpf_bypass", "", "", {}, {}, 0, kPortGroupNone,
-};
-#endif
-
 /**
    Port Group.@n
    Allows to group together audio/cv ports or parameters.