[libxslt] Add required MinGW-w64 packages for libxml2 to CI

[Nick Wellnhofer <nwellnhof src gnome org>]

commit 94b755935cc7856955f61c932506da6346e8b2e8
Author: Markus Rickert <rickert fortiss org>
Date:   Mon Nov 30 12:55:39 2020 +0100

    Add required MinGW-w64 packages for libxml2 to CI

 .gitlab-ci.yml | 5 +++++
 1 file changed, 5 insertions(+)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 3c7d035a..ca8d9293 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -113,7 +113,12 @@ cmake:linux:clang:static:
     - pacman --noconfirm -Syu
     - pacman --noconfirm -S
         $Env:MINGW_PACKAGE_PREFIX-cmake
+        $Env:MINGW_PACKAGE_PREFIX-libiconv
+        $Env:MINGW_PACKAGE_PREFIX-ninja
+        $Env:MINGW_PACKAGE_PREFIX-python
         $Env:MINGW_PACKAGE_PREFIX-python2
+        $Env:MINGW_PACKAGE_PREFIX-xz
+        $Env:MINGW_PACKAGE_PREFIX-zlib
     - if (-not (Test-Path 7za.exe)) {
         Invoke-WebRequest -Uri https://www.7-zip.org/a/7z1900-extra.7z -OutFile 7z1900-extra.7z ;
         cmake -E tar xf 7z1900-extra.7z 7za.exe