.github/zephyr: try to re-use already installed msys64

This should save 20-30s and reduce the number of variables

Signed-off-by: Marc Herbert <marc.herbert@intel.com>

.github/workflows/zephyr.yml

@@ -333,14 +333,12 @@ jobs:
  ninja.exe --version
 
  # MSYS2 provides gcc x64_86 toolchain & openssl
- # Installs in D:/a/_temp/msys64
- #
- # Note there is already C:/msys64/ provided by
- # https://github.com/actions/runner-images/blob/win22/20230918.1/images/win/Windows2022-Readme.md
- # Is it not good enough? Maybe it could save 20-30s.
  - name: Initialize MSYS2
  uses: msys2/setup-msys2@v2
  with:
+ # Try to re-use c:/msys64 which is already there
+ # https://github.com/actions/runner-images/blob/win22/20230918.1/images/win/Windows2022-Readme.md
+ release: false
  msystem: MSYS
  install: gcc openssl-devel
  path-type: inherit