chore: Improve tool detection in test script

Suggested-by: firewave <firewave@users.noreply.github.com>

Author: jcfr

run-tests.py

@@ -24,8 +24,13 @@ def cleanup(out):
 if not GCC_EXE:
     sys.exit('Failed to run tests: gcc compiler not found')
 
-os.environ["PATH"] = os.getcwd() + os.pathsep + os.environ["PATH"]
+# Check if simplecpp is in the PATH
 SIMPLECPP_EXE = shutil.which('simplecpp')
+# If not found in PATH, try current directory
+if not SIMPLECPP_EXE:
+    candidate = os.path.join(os.getcwd(), "simplecpp")
+    if os.path.isfile(candidate) and os.access(candidate, os.X_OK):
+        SIMPLECPP_EXE = candidate
 if not SIMPLECPP_EXE:
     sys.exit('Failed to run tests: simplecpp compiler not found')