Incremental replication behaves inconsistently with parquet partitioning.

[sebastianswms]

When using parquet partitioning, only a subset of files are loaded. The incremental replication key is modified based on these subset of files, meaning that other files with older last_modified dates might be skipped unintentionally. Not easy to workaround without a reimplementation of partitioning logic, and I'm not sure it's desirable either (would necessitate reading metadata for files that don't match the user's filters).