[pygobject] CI: switch to the new win32 powershell runners

[Christoph Reiter <creiter src gnome org>]

commit 6e878fe694ef2fbfef6d9a9f95b649770ded8636
Author: Christoph Reiter <reiter christoph gmail com>
Date:   Tue Apr 28 09:22:03 2020 +0200

    CI: switch to the new win32 powershell runners

 .gitlab-ci.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index b12e3dc5..5db5b26f 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -20,7 +20,7 @@ cache:
 .mingw-defaults: &mingw-defaults
   stage: build_and_test
   tags:
-    - win32
+    - win32-ps
   artifacts:
     paths:
       - coverage/