release: check the licences in the installed package's file list

The Ubuntu and Fedora container images skip documentation when installing, so
the file is missing on disk even though the package carries it.

Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01UhhZMBTviDQxZvwnyP89fo

.github/workflows/release.yml

@@ -171,17 +171,19 @@ jobs:
         run: |
           # The oldest supported Ubuntu (the build's glibc) and a current Fedora. Recommended and
           # weak dependencies (GPU drivers) are skipped to keep it quick; the hard ones must resolve.
+          # Both images leave out documentation when installing (dpkg path-exclude, dnf nodocs), so
+          # the licences are checked in the package's file list rather than on disk.
           docker run --rm -v "$PWD/dist/release:/dist:ro" ubuntu:22.04 bash -euxc '
             apt-get update -qq
             DEBIAN_FRONTEND=noninteractive apt-get install -y -qq --no-install-recommends /dist/*.deb
             fieldcraft-cli --version
             fieldcraft --version
-            test -f /usr/share/doc/fieldcraft/THIRD-PARTY-LICENSES.txt'
+            dpkg -L fieldcraft | grep -Fx /usr/share/doc/fieldcraft/THIRD-PARTY-LICENSES.txt'
           docker run --rm -v "$PWD/dist/release:/dist:ro" fedora:44 bash -euxc '
             dnf install -y -q --setopt=install_weak_deps=False /dist/*.rpm
             fieldcraft-cli --version
             fieldcraft --version
-            test -f /usr/share/doc/fieldcraft/THIRD-PARTY-LICENSES.txt
+            rpm -ql fieldcraft | grep -Fx /usr/share/doc/fieldcraft/THIRD-PARTY-LICENSES.txt
             dnf install -y -q rpmlint
             rpmlint /dist/*.rpm || true'
       - uses: actions/upload-artifact@cf430e030ddbb5b0abf93d22962f4752f3646cd9 # v7.0.2