Update to Substrait v0.94.0

[substrait-project-bot]

Release Notes

0.94.0 (2026-06-14)

Features

• allow for function composition in test cases (#1088) (4e1ee3e)
• tests: support user-defined type literals in test cases (#1098) (5ff4dc4)

See https://github.com/substrait-io/substrait/releases/tag/v0.94.0

[nielspardon]

Implemented by #204 (spec bump to 0.96.0). Both v0.94.0 features (#1088 function composition, #1098 user-defined type literals) are scoped to the spec repo's .test test-case file format.

substrait-python does not consume spec .test files, so both are covered by the pin bump.

(General tooling to consume the spec's .test files is being considered as a separate epic.)