windows-11-arm has only C drive

Author: hsbt

.github/workflows/windows.yml

@@ -63,6 +63,7 @@ jobs:
       GITPULLOPTIONS: --no-tags origin ${{ github.ref }}
       OS_VER: windows-${{ matrix.os < 2022 && '2019' || matrix.os }}
       VCPKG_DEFAULT_TRIPLET: ${{ matrix.target || 'x64' }}-windows
+      RUBY_OPT_DIR: ${{ matrix.os == '11-arm' && 'C' || 'D' }}:/a/ruby/ruby/src/vcpkg_installed/%VCPKG_DEFAULT_TRIPLET%
 
     steps:
       - run: md build
@@ -146,7 +147,7 @@ jobs:
       - name: Configure
         run: >-
           ../src/win32/configure.bat --disable-install-doc
-          --with-opt-dir=D:/a/ruby/ruby/src/vcpkg_installed/%VCPKG_DEFAULT_TRIPLET%
+          --with-opt-dir=%RUBY_OPT_DIR%
           --with-gmp
 
       - run: nmake prepare-vcpkg