[Archery][Integration] Rename "language" to "implementation"

### Describe the enhancement requested

Because there is not a language, nanoarrow, for integration test targets.

See also: https://github.com/apache/arrow/pull/44099#discussion_r1763142729

### Component(s)

Developer Tools, Integration