CI: use the new setup-msys2 output for finding the install location

.github/workflows/generate-srcinfo.yml

@@ -31,6 +31,7 @@ jobs:
           pipx install --python '${{ steps.setup-python.outputs.python-path }}' git+https://github.com/msys2/msys2-devtools
 
       - uses: msys2/setup-msys2@v2
+        id: msys2
         with:
           msystem: MSYS
           update: true
@@ -45,8 +46,7 @@ jobs:
 
       - name: Parse PKGBUILDs and update srcinfo.json.gz
         run: |
-          $MSYS2_ROOT=(msys2 -c 'cygpath -w /')
-          msys2-srcinfo-cache --time-limit 19800 mingw "$MSYS2_ROOT" . srcinfo.json.gz
+          msys2-srcinfo-cache --time-limit 19800 mingw '${{ steps.msys2.outputs.msys2-location }}' . srcinfo.json.gz
 
       - name: Update the PyPI cache
         run: |