CI: Remove workaround for Python in MSYS2 jobs

It was added in 13fe2e0, but it's now unnecessary as the issue
has been fixed.

See msys2/MINGW-packages#17415

.gitlab-ci.yml

@@ -341,10 +341,6 @@ msys2-mingw32:
     CHERE_INVOKING: "yes"
     CFLAGS: -coverage -ftest-coverage -fprofile-arcs
     PYTHONUTF8: "1"
-    # FIXME: For some reason enabling jit debugging "fixes" random python crashes
-    # see https://github.com/msys2/MINGW-packages/issues/11864 and
-    # https://gitlab.gnome.org/GNOME/glib/-/merge_requests/3280#note_1678973
-    MSYS: "winjitdebug"
   script:
     - C:\msys64\usr\bin\pacman --noconfirm -Syyuu --ask 20
     - C:\msys64\usr\bin\bash .gitlab-ci/show-execution-environment.sh
@@ -371,10 +367,6 @@ msys2-clang64:
     MSYSTEM: "CLANG64"
     CHERE_INVOKING: "yes"
     PYTHONUTF8: "1"
-    # FIXME: For some reason enabling jit debugging "fixes" random python crashes
-    # see https://github.com/msys2/MINGW-packages/issues/11864 and
-    # https://gitlab.gnome.org/GNOME/glib/-/merge_requests/3280#note_1678973
-    MSYS: "winjitdebug"
   script:
     - C:\msys64\usr\bin\pacman --noconfirm -Syyuu --ask 20
     - C:\msys64\usr\bin\bash .gitlab-ci/show-execution-environment.sh