🚸 Portability improvements for the QIR runner (#1410)

## Description

Picked from #1403.
Improves the portability of the QIR runner by relying on less platform
specific functions.

## Checklist:

<!---
This checklist serves as a reminder of a couple of things that ensure
your pull request will be merged swiftly.
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- [x] The pull request only contains commits that are focused and
relevant to this change.
- [x] I have added appropriate tests that cover the new/changed
functionality.
- [x] I have updated the documentation to reflect these changes.
- [x] I have added entries to the changelog for any noteworthy
additions, changes, fixes, or removals.
- [x] I have added migration instructions to the upgrade guide (if
needed).
- [x] The changes follow the project's style guidelines and introduce no
new warnings.
- [x] The changes are fully tested and pass the CI checks.
- [x] I have reviewed my own code changes.

---------

Signed-off-by: burgholzer <burgholzer@me.com>
(cherry picked from commit 3bef3a6)

Author: burgholzer

test/qir/runner/test_qir_runner.cpp

@@ -13,12 +13,6 @@
 #include <gtest/gtest.h>
 #include <sstream>
 
-#ifdef _WIN32
-#define SYSTEM _wsystem
-#else
-#define SYSTEM std::system
-#endif
-
 namespace qir {
 class QIRRunnerTest : public testing::TestWithParam<std::filesystem::path> {};
 
@@ -37,8 +31,8 @@ INSTANTIATE_TEST_SUITE_P(
 TEST_P(QIRRunnerTest, QIRFile) {
   const auto& file = GetParam();
   std::ostringstream command;
-  command << EXECUTABLE_PATH << " " << file;
-  const auto result = SYSTEM(command.str().c_str());
+  command << "\"" << EXECUTABLE_PATH << "\" \"" << file << "\"";
+  const auto result = std::system(command.str().c_str());
   EXPECT_EQ(result, 0);
 }
 } // namespace qir

test/qir/runtime/CMakeLists.txt

@@ -21,6 +21,7 @@ macro(ADD_QIR_CIRCUIT target_name circuit_path)
       COMMENT "Compiling ${circuit_path} to ${circuit_name}.o")
     add_executable(${target_name} ${circuit_name}.o)
     target_link_libraries(${target_name} PRIVATE MQT::CoreQIRRuntime)
+    set_target_properties(${target_name} PROPERTIES LINKER_LANGUAGE CXX)
   endif()
 endmacro()