Improved efficiency of windows acceptance test workflow by not re-installing msys2

msys2 is included in github windows images, e.g. https://github.com/actions/runner-images/tree/main/images/windows

Ticket: ENT-11771
Changelog: none

Author: craigcomstock

.github/workflows/windows_acceptance_tests.yml

@@ -11,14 +11,8 @@ jobs:
   windows_acceptance_tests:
     runs-on: windows-latest
     steps:
-      - uses: msys2/setup-msys2@v2
-        with:
-          install: >-
-            rsync
-            dos2unix
-            diffutils
-            util-linux
-            python-pip
+      - name: Install msys2 packages
+        run: pacman -S rsync dos2unix diffutils util-linux python-pip
 
       - name: Checkout Core
         uses: actions/checkout@v3