Remove pyqtgraph requirement

Edgar Reehuisrequested to merge
remove-pyqtgraph-dep into main

Removing pyqtgraph requirement as it is pinned too in last quantify-core v0.7.0 release

Note: the upcoming quantify-core release will remove the pin on pyqtgraph by bumping qcodes>=0.37.0 (see quantify-core!439 (merged))

Merge request reports