v0.4.18 release

What's Changed

• Cleanup docs by @cthoyt in #621
• Add alternate dataframe split implementations by @cthoyt in #608
• Require RDFLib 7.1.3 at a minimum. by @gouttegd in #623
• Fix support for literal mappings. by @gouttegd in #624
• Use latest pre-release of the SSSOM schema. by @gouttegd in #625
• Add method to enforce compliance with a given version of the SSSOM specification. by @gouttegd in #616
• Fix msdf_merge util function. by @gouttegd in #627
• Update SSSOM Extended Prefix Map by @github-actions[bot] in #601
• Automatically propagate/condense slots when parsing/writing. by @gouttegd in #629
• Make stricter type checking by @cthoyt in #634
• Use custom code for RDF (de)serialisation by @gouttegd in #635
• Update type ignore comments and fix row indexing by @matentzn in #639
• Use packaging to parse pandas version by @matentzn in #638

Full Changelog: v0.4.17...v0.4.18