Build(deps): Bump actions/download-artifact from 5 to 6

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 5 to 6.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@v5...v6)

---
updated-dependencies:
- dependency-name: actions/download-artifact
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/ci_cd.yml

@@ -414,7 +414,7 @@ jobs:
           repository: ansys-internal/signtool-ansys-apps
           token: ${{ secrets.SIGNTOOL_ACCESS_TOKEN }}
 
-      - uses: actions/download-artifact@v5
+      - uses: actions/download-artifact@v6
         with:
           name: Python-Installer-windows
           path: signtool/installer
@@ -468,32 +468,32 @@ jobs:
       - build-application-linux-non-debian
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/download-artifact@v5
+      - uses: actions/download-artifact@v6
         with:
           name: Python-Installer-windows-signed
           path: installer-signed
 
-      - uses: actions/download-artifact@v5
+      - uses: actions/download-artifact@v6
         with:
           name: Python-Installer-windows
           path: installer
 
-      - uses: actions/download-artifact@v5
+      - uses: actions/download-artifact@v6
         with:
           name: Python-Installer-ubuntu_24.04
           path: installer
 
-      - uses: actions/download-artifact@v5
+      - uses: actions/download-artifact@v6
         with:
           name: Python-Installer-ubuntu_22.04
           path: installer
 
-      - uses: actions/download-artifact@v5
+      - uses: actions/download-artifact@v6
         with:
           name: Python-Installer-centos_stream9
           path: installer
 
-      - uses: actions/download-artifact@v5
+      - uses: actions/download-artifact@v6
         with:
           name: Python-Installer-fedora_40
           path: installer