Escapes Variables to avoid erros during evaluation by Gitlab-runner (especially at the start of the string)

Use Invoke Expression to workaround the variables evaluation issue

Set up missing var to get right environment for code signing
Add missing artifact for code signing job

.gitlab-ci-files/windows-desktop.yml

@@ -206,6 +206,8 @@ win64-codesigning:
     - .windows-codesigning
   needs:
     - win64-ninja-vs2022-package-windows
+  variables:
+    MINGW_TYPE: mingw64
   rules:
     - !reference [.rules-merge-request-manual, rules]
     - if: $NIGHTLY_MASTER
@@ -213,7 +215,12 @@ win64-codesigning:
     - if: $DEPLOY_WINDOWS
   script:
     - cd build-desktop/OUTPUT/Packages/
-    - ${WINDOWS_SIGN_TOOL} sign /fd SHA256 /t ${WINDOWS_SIGN_TIMESTAMP_URL} /sha1 ${WINDOWS_SIGN_HASH} *.exe
+    - Invoke-Expression "& ${WINDOWS_SIGN_TOOL} sign /fd SHA256 /t ${WINDOWS_SIGN_TIMESTAMP_URL} /sha1 ${WINDOWS_SIGN_HASH} *.exe"
+  artifacts:
+    paths:
+      - build-desktop\OUTPUT\Packages\*
+    when: always
+    expire_in: 1 week
 
 #################################################
 #               DEPLOY