Update imbalanced-learn requirement in /scripts/nb-tester

Updates the requirements on [imbalanced-learn](https://github.com/scikit-learn-contrib/imbalanced-learn) to permit the latest version.
- [Release notes](https://github.com/scikit-learn-contrib/imbalanced-learn/releases)
- [Commits](scikit-learn-contrib/imbalanced-learn@0.12.3...0.14.2)

---
updated-dependencies:
- dependency-name: imbalanced-learn
  dependency-version: 0.14.2
  dependency-type: direct:production
...

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

Author: dependabot[bot]

scripts/nb-tester/requirements.txt

@@ -31,4 +31,4 @@ qiskit-basis-constructor~=0.1.0
 qiskit_addon_slc~=0.1.0
 mthree~=2.8.1
 qctrl-visualizer~=11.0.0
-imbalanced-learn~=0.12.3
+imbalanced-learn~=0.14.2