[gobject-introspection] CI: move from mingw32 to mingw64

[Christoph Reiter <creiter src gnome org>]

commit 17563f9969cf5c845c84cc5470476175fc270adf
Author: Christoph Reiter <reiter christoph gmail com>
Date:   Sun May 9 12:13:12 2021 +0200

    CI: move from mingw32 to mingw64
    
    ccache is currently broken somehow. With 32bit Windows getting less and less
    usage/testing it's a good idea to move to 64 bit anyway.

 .gitlab-ci.yml                 | 4 ++--
 .gitlab-ci/test-msys2-meson.sh | 1 -
 2 files changed, 2 insertions(+), 3 deletions(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 10124cb5..df720e3f 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -109,12 +109,12 @@ fedora-x86_64-python3.6:
       - "${CI_PROJECT_DIR}/_build/meson-logs"
       - public
 
-msys2-mingw32-meson:
+msys2-mingw64-meson:
   stage: build
   tags:
     - win32-ps
   variables:
-    MSYSTEM: "MINGW32"
+    MSYSTEM: "MINGW64"
     CHERE_INVOKING: "yes"
   script:
     - C:\msys64\usr\bin\pacman --noconfirm -Syyuu --ask 20
diff --git a/.gitlab-ci/test-msys2-meson.sh b/.gitlab-ci/test-msys2-meson.sh
index 56f8c9b3..06d3c2a6 100644
--- a/.gitlab-ci/test-msys2-meson.sh
+++ b/.gitlab-ci/test-msys2-meson.sh
@@ -2,7 +2,6 @@
 
 set -e
 
-export PATH="/c/msys64/$MSYSTEM/bin:$PATH"
 if [[ "$MSYSTEM" == "MINGW32" ]]; then
     export MSYS2_ARCH="i686"
 else