dev: commit working tzdata to repo

[tommilligan]

Ship a version of the tzdata files that our old haskell/duckling code is happy to open.

There was a discussion here: https://reinfer.slack.com/archives/C0APLNE23/p1740651201063489

I looked into pulling packages from older Ubuntu/Debian versions and found the implications/packaging constraints way more complicated than we needed it to be - this PR simply zips up a bunch of files we need, so we can unpack them in the right place.

We already rely on the source code from this repo, and the archive is <1MB. I'm happy to just inline what we know works here.

Added instructions in this PR of how to reproduce the stored data archive, but inlining for reference:

# Outputs .deb file in ./data directory
docker run --rm -it -v "$(pwd)/data:/mnt/data" ubuntu:20.04 /bin/bash -c 'apt-get update && apt-get download tzdata && mv /tzdata* /mnt/data'