Update install to ensure the build directory is not added to the rpath

This seems to be fine with the existing CMake, but in 3.29 (possibly
earlier) the rpath of libTesting still has the build directory. Make
sure to remove any existing build rpath.

Author: bnbarham

Diff for: cmake/modules/SwiftModuleInstallation.cmake

@@ -46,11 +46,13 @@ function(_swift_testing_install_target module)
   target_compile_options(Testing PRIVATE "-no-toolchain-stdlib-rpath")
 
   if(APPLE)
-    set_property(TARGET ${module} PROPERTY
-      INSTALL_RPATH "@loader_path/..")
+    set_target_properties(${module} PROPERTIES
+      INSTALL_RPATH "@loader_path/.."
+      INSTALL_REMOVE_ENVIRONMENT_RPATH ON)
   else()
-    set_property(TARGET ${module} PROPERTY
-      INSTALL_RPATH "$ORIGIN")
+    set_target_properties(${module} PROPERTIES
+      INSTALL_RPATH "$ORIGIN"
+      INSTALL_REMOVE_ENVIRONMENT_RPATH ON)
   endif()
 
   get_target_property(type ${module} TYPE)