Improve code quality and test coverage

[schlunma]

Description

While working on #3025, I noticed that we often have the pattern

msg = "error message"
raise Exception(
    msg,
)

in our code base, which has been introduced by Ruff. This PR fixes this.

It also improves our test coverage by adding missing tests for the changed lines (thanks Claude!).

---

Checklist

It is the responsibility of the author to make sure the pull request is ready to review. The icons indicate whether the item will be subject to the 🛠 Technical or 🧪 Scientific review.

• 🧪 The new functionality is relevant and scientifically sound
• 🛠 This pull request has a descriptive title and labels
• 🛠 Code is written according to the code quality guidelines
• 🧪 and 🛠 Documentation is available
• 🛠 Unit tests have been added
• 🛠 Changes are backward compatible
• 🛠 Any changed dependencies have been added or removed correctly
• 🛠 The list of authors is up to date
• 🛠 All checks below this pull request were successful

---

To help with the number pull requests:

• 🙏 We kindly ask you to review two other open pull requests in this repository

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 96.14%. Comparing base (9e24b51) to head (5578a33).
⚠️ Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3029      +/-   ##
==========================================
+ Coverage   95.70%   96.14%   +0.44%     
==========================================
  Files         267      267              
  Lines       15768    15768              
==========================================
+ Hits        15090    15160      +70     
+ Misses        678      608      -70     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[valeriupredoi]

LGTM thanks Manu 🍻