Use force_zip64=True when directly creating .conda files

[dholth]

Description

Address same issue as https://github.com/conda/conda-package-streaming/issues/79 but when creating .conda directly (handled by conda-package-handling) , not converting from .tar.bz2 (handled by conda-package-streaming).

Fix #248

Tested by running dd if=/dev/urandom of=random bs=1M count=2048 and cph c . /tmp/big.conda, which will create a 2147533062-byte pkg-big.tar.zst, fail on the older code and succeed after this fix.

Checklist - did you ...

• [x] Add a file to the news directory (using the template) for the next release's release notes?
• [x] Add / update necessary tests?
• [x] Add / update outdated documentation?