Work on build-tarball: Without libselinux, chcon and runcon are not built, and "make distcheck" fails.

Author: bhaible

.github/workflows/many-platforms.yml

@@ -57,7 +57,7 @@ jobs:
       - run: pwd
       # Install Ubuntu packages.
       # List of packages: https://packages.ubuntu.com/
-      - run: sudo apt update; sudo apt install autopoint gperf gettext texlive-base texlive-latex-base
+      - run: sudo apt update; sudo apt install autopoint gperf gettext texlive-base texlive-latex-base libselinux1-dev
       - run: |
           ./build-tarball.sh '${{ env.package }}'
       # Doc: https://github.com/actions/upload-artifact?tab=readme-ov-file#usage