PPC64LE CI still runs its build and packaging stream on IBM hosts. Move the RHEL 8.1, 9, and 10 release and shared variants onto the same ARM64 cross-build strategy as s390x, while retaining native PPC64LE dbtests, integration tests, unit tests, and server-version recording. Waterfall release builds retain fully local execution and cache restrictions on the ARM64 build host.

Native resmoke tasks receive a separate PPC64LE Python environment, and publishing retains its existing test gates. Correct the RHEL 8.1 and 9 shared variants' artifact paths to use their actual `-dynamic` variant names.