Update mthree requirement from ~=2.8.1 to ~=3.0.0 in /scripts/nb-tester

Updates the requirements on [mthree](https://github.com/Qiskit/qiskit-addon-mthree) to permit the latest version.
- [Release notes](https://github.com/Qiskit/qiskit-addon-mthree/releases)
- [Commits](Qiskit/qiskit-addon-mthree@v2.8.1...v3.0)

---
updated-dependencies:
- dependency-name: mthree
  dependency-version: 3.0.0
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

scripts/nb-tester/requirements.txt

@@ -29,6 +29,6 @@ qiskit-paulice~=0.2.1
 category_encoders~=2.10.0
 qiskit-basis-constructor~=0.1.0
 qiskit_addon_slc~=0.1.0
-mthree~=2.8.1
+mthree~=3.0.0
 qctrl-visualizer~=11.0.0
 imbalanced-learn~=0.12.3