adds python sdk to sourceDependencies. adds new field "core" to sourc…

[MarkAckert]

Adds zowe-client-python-sdk as a sourceDependency to be tracked by downstream automation. This is in response to zowe/zowe-dependency-scan-pipeline#154 .

This PR also creates a new field in a sourceDependency entry called 'core', which if not present should be assumed to default to true. This field lets downstream automation better decide how to handle non-core projects going forward.

[github-actions]

build 6543 SUCCEEDED.
Link to workflow run: https://github.com/zowe/zowe-install-packaging/actions/runs/12167884232

[github-actions]

Test workflow 5761 is started.
Running install test: Convenience Pax
The zowe artifact being used by this test workflow: libs-snapshot-local/org/zowe/3.1.0-PR-4102/zowe-3.1.0-pr-4102-6543-20241204204316.pax
Running on machine: zzow09
Result: SUCCESS
Link to workflow run: https://github.com/zowe/zowe-install-packaging/actions/runs/12167976366

[github-actions]

build 6544 SUCCEEDED.
Link to workflow run: https://github.com/zowe/zowe-install-packaging/actions/runs/12168280553

[github-actions]

Test workflow 5762 is started.
Running install test: Convenience Pax
The zowe artifact being used by this test workflow: libs-snapshot-local/org/zowe/3.1.0-PR-4102/zowe-3.1.0-pr-4102-6544-20241204210943.pax
Running on machine: zzow11
Result: SUCCESS
Link to workflow run: https://github.com/zowe/zowe-install-packaging/actions/runs/12168355473