ci(rp-4): Windows CLI — install zip via choco + as_posix() on ORT_CAPI

build-cli-windows v0.1.7 (CI run 26522212284) still failed at 'Package
zip' despite the bsdtar fallback in package_cli_tarball.sh. Root cause:
Git Bash on windows-latest shadows the Windows-native tar.exe (bsdtar)
with its own GNU /usr/bin/tar, so the bsdtar-detection branch never
fires, and the standalone zip binary is also absent from default PATH.

Fixes:
- Stage ORT runtime: emit ORT_STAGE_DIR with .as_posix() so the
  path uses forward slashes consistently; mixed slashes from default
  pathlib repr (C:\foo\bar) caused the script's bash tests to behave
  inconsistently under MSYS.
- New step 'Install zip via choco' before the packaging step. choco
  is pre-installed on windows-latest runners; the zip package wraps
  the standard Info-ZIP build. Once zip is on PATH, the existing
  script branch picks it up.

This is belt-and-suspenders: even if bsdtar detection had worked,
having zip available is the more portable answer (matches what the
macOS / Linux jobs implicitly assume — that their packaging
primitive is on PATH).

Recovery: cut v0.1.8 from this HEAD to validate.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: zhmiao

.github/workflows/release.yml

@@ -723,9 +723,17 @@ jobs:
           rm -rf "$ORT_VENV"
           python3 -m venv "$ORT_VENV"
           "$ORT_VENV/Scripts/pip" install --quiet "onnxruntime>=1.25.1,<1.26"
-          ORT_CAPI=$("$ORT_VENV/Scripts/python" -c "import onnxruntime, pathlib; print(pathlib.Path(onnxruntime.__file__).parent / 'capi')")
+          # `.as_posix()` so the path uses forward slashes even on Windows
+          # (default pathlib repr is `C:\foo\bar`). The packaging script's
+          # bash path tests (`[[ -d $ort_capi ]]`) and command substitutions
+          # are more reliable with forward slashes under Git Bash + MSYS.
+          ORT_CAPI=$("$ORT_VENV/Scripts/python" -c "import onnxruntime, pathlib; print((pathlib.Path(onnxruntime.__file__).parent / 'capi').as_posix())")
           echo "ORT_STAGE_DIR=$ORT_CAPI" >> "$GITHUB_ENV"
 
+      - name: Install zip (MSYS Git Bash does not ship it by default)
+        shell: pwsh
+        run: choco install zip -y --no-progress --no-color
+
       - name: Build spe.exe (release, CPU flavor, Windows x86_64)
         working-directory: sparrow-engine
         shell: bash