fix: raise the osx-64 PyPI platform tag to macOS 10.15

[crowecawcaw]

What was the problem/requirement? (What/Why)

scripts/create_adaptor_packaging_artifact.sh resolves the adaptor's dependencies for osx-64 against the PyPI platform tag macosx_10_9_x86_64. macOS 10.9 shipped in 2013. pip treats the tag as a ceiling — it accepts any wheel built for an equal or older deployment target — so the effect is not "supports old macOS", it is "silently pins every dependency to whatever version last published a 10.9 build."

Resolving the adaptor for Python 3.11 under each tag, same package set, different versions:

package	macosx_10_9_x86_64	macosx_10_15_x86_64
rpds-py	0.13.2	2026.6.3
PyYAML	6.0.2	6.0.3
jsonschema	4.25.1	4.26.0

rpds-py is the notable one: the old tag holds it years behind because upstream stopped publishing a 10.9 wheel. Packages that publish no 10.9 wheel at all are excluded outright rather than downgraded — awscrt is one, its macOS wheels start at macosx_10_15_universal2, which is a blocker for anything that needs it (see #525).

What was the solution? (How)

Raise the tag to macosx_10_15_x86_64. Because pip accepts wheels built for equal-or-older targets, 10.15 is a strict superset of 10.9 — no wheel that resolved before stops resolving.

The other deadline-cloud-for-* repos carry the same macosx_10_9_x86_64 line in their copy of this script. This change is scoped to Cinema 4D.

What is the impact of this change?

The osx-64 adaptor conda artifact picks up current builds of its native dependencies instead of ones frozen by a 2013 deployment target, and packages with a 10.15 wheel floor become resolvable. macOS is not a supported fleet platform for this integration today (README: Windows and Linux fleets), so nothing in the shipped render path changes. No adaptor interface, schema, submitter, or job-bundle change.

How was this change tested?

The script is not invoked by any workflow in this repo, so it was run by hand. bash scripts/create_adaptor_packaging_artifact.sh --platform osx-64 --python 3.11 completes successfully and produces the tar artifact, installing pyyaml 6.0.3, rpds-py 2026.6.3, and jsonschema 4.26.0 where the old tag installs 6.0.2, 0.13.2, and 4.25.1. The version table above comes from pip install --dry-run --report under each tag, with --only-binary=:all: --python-version 3.11, confirming the package set is identical and only the selected builds differ.

• Unit tests: not run — no Python source changed.
• Integration tests: not applicable.
• Submitter changes: none.

Was this change documented?

No documentation change needed. The tag is an internal packaging detail and no public interface or schema changed.

Is this a breaking change?

No. It relaxes wheel selection rather than restricting it, and does not touch the adaptor interface, the init-data or run-data schemas, or job-bundle compatibility.

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