Update to Substrait v0.91.0

[nielspardon]

Release Notes

0.91.0 (2026-05-17)

⚠ BREAKING CHANGES

• extensions: changes the return type of the subtract:date_iday
  function from date to precision_timestamp

Features

• clarify post_join_filter. add residual_expressions to hash join and merge join (#1044) (f7b939c), closes #807
• docs: clarify distinction between enumeration arguments and options (#1005) (51ff9fa)

Bug Fixes

• extensions: correct return type for subtract:date_iday operation (#1029) (26fbd04)

See https://github.com/substrait-io/substrait/releases/tag/v0.91.0