Fix some issues reported by lintian

Fix some issues reported by lintian

• Bump debhelper from old 10 to 13. (package-uses-old-debhelper-compat-version)
• Set upstream metadata fields: Bug-Database, Bug-Submit, Name, Repository-Browse. (upstream-metadata-file-is-missing, upstream-metadata-missing-bug-tracking)
• Remove field Section on binary package python3-pyzabbix that duplicates source. (installable-field-mirrors-source)
• Set upstream metadata fields: Repository. (upstream-metadata-missing-repository)

These changes have no impact on the binary debdiff.

You can also view the diffoscope diff (unfiltered).

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Build and test logs for this branch can be found at https://janitor.debian.net/run/df47f303-b8f6-491d-83c8-a71ed992f441.