Replace karma; Update `jasmine-core`

We use karma for running our jasmine unit tests via the command line, particularly for CI. Recently, [karma has been deprecated](https://github.com/karma-runner/karma#karma-is-deprecated-and-is-not-accepting-new-features-or-general-bug-fixes).

We'll need to find a replacement workflow. Karma's docs suggest:

> Both [Web Test Runner](https://modern-web.dev/docs/test-runner/overview/) and [jasmine-browser-runner](https://github.com/jasmine/jasmine-browser-runner) provide browser-based unit testing solutions which can be used as a direct alternative. [Jest](https://jestjs.io/) and [Vitest](https://vitest.dev/) also provide Node-based alternatives.

Start by reviewing Karma's deprecation notice and comparing the listed alternatives: Web Test Runner, jasmine-browser-runner, Jest, and Vitest. Done means the Jasmine unit tests run from the command line and in CI without Karma, with jasmine-core updated as needed.

Written by the indexing model from the issue text.