pinned qcodes to working version

[marcosfrenkel]

Summary

• Pin qcodes<0.55 in pyproject.toml so the server stops crashing on import.
• qcodes 0.55.0 removed InstrumentBase from the deprecated qcodes.instrument.base path, which breaks four import sites in this repo (blueprints.py, client/proxy.py, params.py, serialize.py). 0.54.4 is the last compatible release.
• uv.lock updated to resolve qcodes==0.54.4 (and the transitive pyvisa pin that comes with it).

This is a stopgap. The real fix — migrating the imports to from qcodes.instrument import InstrumentBase — is tracked in #131; once that lands the pin can be lifted.

Test plan

• uv sync resolves cleanly with qcodes==0.54.4.
• uv run instrumentserver starts without the ImportError on qcodes.instrument.base.
• uv run pytest passes.