bioperl-core: add missing depends on perl-db_file

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The Bio::Index module needs perl-db_file to enable the creation of index files. perl-bio-searchio-hmmer, which I'm trying to add in #33805, indirectly uses this functionality via the parent class here, which made tracing the test failure I saw while testing that package really time consuming. it's not the only module to do so (e.g. Bio::AlignIO::stockholm also inherits from this class), and the dependency really belongs here because it's the interface defined here in bioperl-core that made the decision to go with perl-db_file, not anything that searchio-hmmer has any part in.

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[0xaf1f]

@BiocondaBot please add label

[0xaf1f]

Looks like the comprehensive PR #33805 will work out after all.

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@BiocondaBot please remove label