[3.1-RC1] Add target removal versions to the AI/Dataset deprecation notices

[henrylyons]

Affected Sections: model/AI/Properties/autonomyType.md and related

Feedback
The four deprecation notices (autonomyType, datasetSize, intendedUse, customIdToUri) say only 'will be removed in a future release' with no version target.

Suggested Change:
Specify a target removal version so vendors can plan migrations. (model/AI/Properties/autonomyType.md and related)

Notes:
This feedback was provided by Microsoft at the SPDX working group meeting on June 30, 2026.

[bact]

Those deprecated properties have to be there for the entire SPDX 3.x series for backward compatibility.

We can remove them in SPDX 4.