Removes migration stub headers superseded by codegen outputs

Drops 184 stub headers and obsolete stub tests now generated in the build tree.

qt6-after/qt6-migrated-legatus/Lts/Services/EffectShowClient/esc_dtc.h

@@ -1,7 +0,0 @@
-#ifndef _STUB_DTC_H
-#define _STUB_DTC_H
-// Stub file for BUILD_GRANTLEE=OFF
-namespace ESC {
-    class Dtc {};
-}
-#endif

qt6-after/qt6-migrated-legatus/Lts/Services/EffectShowClient/esc_ftc.h

@@ -1,7 +0,0 @@
-#ifndef _STUB_FTC_H
-#define _STUB_FTC_H
-// Stub file for BUILD_GRANTLEE=OFF
-namespace ESC {
-    class Ftc {};
-}
-#endif