Fix some issues reported by lintian

See merge request !1

Changes-By: lintian-brush
Fixes: lintian: out-of-date-standards-version
See-also: https://lintian.debian.org/tags/out-of-date-standards-version.html

Changes-By: lintian-brush
Fixes: lintian: upstream-metadata-file-is-missing
See-also: https://lintian.debian.org/tags/upstream-metadata-file-is-missing.html
Fixes: lintian: upstream-metadata-missing-bug-tracking
See-also: https://lintian.debian.org/tags/upstream-metadata-missing-bug-tracking.html
Fixes: lintian: upstream-metadata-missing-repository
See-also: https://lintian.debian.org/tags/upstream-metadata-missing-repository.html

Drop unused python3-sip-dev dependency. (Closes: #984812)