Fix antlr4-cpp-runtime VERSION filename collision on Windows

On case-insensitive filesystems (Windows), antlr4-cpp-runtime's VERSION file collides with C++ standard library <version> header, causing build failures. Adding powershell-based patch_win_cmds to correctly rename it inside Windows Kokoro builds.

PiperOrigin-RevId: 922465750

Author: dmitriplotnikov

MODULE.bazel

@@ -54,6 +54,10 @@ single_version_override(
         "mv VERSION VERSION.txt || true",
         "mv version version.txt || true",
     ],
+    patch_win_cmds = [
+        "powershell -Command \"if (Test-Path VERSION) { Move-Item VERSION VERSION.txt -Force }\"",
+        "powershell -Command \"if (Test-Path version) { Move-Item version version.txt -Force }\"",
+    ],
 )
 
 # Configure rules_python's hermetic toolchains to resolve external

release/kokoro/set_env_windows.bat

@@ -53,7 +53,7 @@ echo Python Version Selected: %PYTHON_VERSION%
 :: Detect Python executable first (needed for downloading BCR assets dynamically)
 set PYTHON_EXE=python
 where python%PYTHON_VERSION% >nul 2>&1
-if !ERRORLEVEL! EQU 0 (
+if %ERRORLEVEL% EQU 0 (
     set PYTHON_EXE=python%PYTHON_VERSION%
 ) else if exist C:\Python%PY_VER_NO_DOT%\python.exe (
     set PYTHON_EXE=C:\Python%PY_VER_NO_DOT%\python.exe