Handle run_tests.py removal in Python 3.13

Author: zanieb

cpython-unix/build-cpython.sh

@@ -912,8 +912,11 @@ cp -av Modules/config.c.in ${ROOT}/out/python/build/Modules/
 cp -av Python/frozen.c ${ROOT}/out/python/build/Python/
 cp -av Modules/Setup* ${ROOT}/out/python/build/Modules/
 
-# Copy the test hardness runner for convenience.
-cp -av Tools/scripts/run_tests.py ${ROOT}/out/python/build/
+# Copy the test harness runner for convenience.
+# In Python 3.13+, this script is not needed to run tests and is not present.
+if [ -d Tools/scripts/run_tests.py ]; then 
+    cp -av Tools/scripts/run_tests.py ${ROOT}/out/python/build/
+fi
 
 mkdir ${ROOT}/out/python/licenses
 cp ${ROOT}/LICENSE.*.txt ${ROOT}/out/python/licenses/

cpython-windows/build.py

@@ -1700,10 +1700,18 @@ def build_cpython(
             log("copying %s to %s" % (source, dest))
             shutil.copyfile(source, dest)
 
-        shutil.copyfile(
-            cpython_source_path / "Tools" / "scripts" / "run_tests.py",
-            out_dir / "python" / "build" / "run_tests.py",
-        )
+        # CPython 3.13 removed `run_tests.py`.
+        if meets_python_minimum_version(python_version, "3.13"):
+            # TODO(zanieb): Write a script to invoke `python -m test --slow-ci`
+            # or update the metadata to not require `run_tests.py`
+            pathlib.Path(
+                out_dir / "python" / "build" / "run_tests.py",
+            ).touch()
+        else:
+            shutil.copyfile(
+                cpython_source_path / "Tools" / "scripts" / "run_tests.py",
+                out_dir / "python" / "build" / "run_tests.py",
+            )
 
         licenses_dir = out_dir / "python" / "licenses"
         licenses_dir.mkdir()