Propagate _Qt6CTestMacros in RunCMake

Propagate the `_Qt6CTestMacros` variable so that
`_qt_internal_get_cmake_test_configure_options` can be used
inside the RunCMake tests

Pick-to: 6.8 6.9 6.10
Change-Id: I2b7f3996315169d840bab3dff011927288c9782d
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>

src/testinternal/3rdparty/cmake/QtRunCMakeTestHelpers.cmake

@@ -20,6 +20,10 @@ macro(add_RunCMake_test test)
   if(CMAKE_C_COMPILER_ID STREQUAL "LCC")
     list(APPEND TEST_ARGS -DRunCMake_TEST_LCC=1)
   endif()
+  # Qt specific options
+  list(APPEND TEST_ARGS
+    -D_Qt6CTestMacros=${_Qt6CTestMacros}
+  )
   add_test(NAME RunCMake.${test} COMMAND ${CMAKE_COMMAND}
     -DCMAKE_MODULE_PATH=${RunCMakeDir}
     -DRunCMake_GENERATOR_IS_MULTI_CONFIG=${_isMultiConfig}

src/testinternal/3rdparty/cmake/patches/0004-Propagate-_Qt6CTestMacros.patch

@@ -0,0 +1,19 @@
+Index: src/testinternal/3rdparty/cmake/QtRunCMakeTestHelpers.cmake
+IDEA additional info:
+Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
+<+>UTF-8
+===================================================================
+diff --git a/src/testinternal/3rdparty/cmake/QtRunCMakeTestHelpers.cmake b/src/testinternal/3rdparty/cmake/QtRunCMakeTestHelpers.cmake
+--- a/src/testinternal/3rdparty/cmake/QtRunCMakeTestHelpers.cmake	(revision b23da37d71bde4673fab3510596514e4ac451053)
++++ b/src/testinternal/3rdparty/cmake/QtRunCMakeTestHelpers.cmake	(revision e71805860401b494ab3b6e1c12eaa1c84fd89994)
+@@ -20,6 +20,10 @@
+   if(CMAKE_C_COMPILER_ID STREQUAL "LCC")
+     list(APPEND TEST_ARGS -DRunCMake_TEST_LCC=1)
+   endif()
++  # Qt specific options
++  list(APPEND TEST_ARGS
++    -D_Qt6CTestMacros=${_Qt6CTestMacros}
++  )
+   add_test(NAME RunCMake.${test} COMMAND ${CMAKE_COMMAND}
+     -DCMAKE_MODULE_PATH=${RunCMakeDir}
+     -DRunCMake_GENERATOR_IS_MULTI_CONFIG=${_isMultiConfig}