FIX: drop tmo fzp att from 6 states to 4 to match plc update

[ZLLentz]

Description

See title The fzp attenuator lost two targets due to space concerns and this new state count had not propagated down to the Python code. I made the required change here.

Motivation and Context

There are some confusing errors if the state count doesn't match. This is probably also something to fix.

How Has This Been Tested?

Ming Fu says he can move the device again

Where Has This Been Documented?

Will make brief pre-release notes

Pre-merge checklist

• [x] Code works interactively
• [x] Code contains descriptive docstrings, including context and API
• [x] New/changed functions and methods are covered in the test suite where possible
• [x] Test suite passes locally
• [x] Test suite passes on GitHub Actions
• [x] Ran docs/pre-release-notes.sh and created a pre-release documentation page
• [x] Pre-release docs include context, functional descriptions, and contributors as appropriate

[ZLLentz]

This is live in dev_conda to let tmo use their screen again