When building releases, don't cancel Debian package builds when one of them fails. (#19842)

When building v1.155.0rc1, flaky deb builds combined with fail-fast
behaviour
meant that I had to press the retry button 5 times to get a full set.

Without fail-fast, I suspect 1 or 2 retries would have done the job.

---------

Signed-off-by: Olivier 'reivilibre <oliverw@matrix.org>
Co-authored-by: Eric Eastwood <erice@element.io>

.github/workflows/release-artifacts.yml

@@ -50,6 +50,12 @@ jobs:
     name: "Build .deb packages"
     runs-on: ubuntu-latest
     strategy:
+      # Prevent all Debian package builds from being cancelled
+      # when one of them fails. Especially helpful when things are
+      # flaky during a release.
+      #
+      # `fail-fast` defaults to true and applies to the entire test matrix
+      fail-fast: false
       matrix:
         distro: ${{ fromJson(needs.get-distros.outputs.distros) }}