Refactor fail() calls in Cursor tests

[ptziegler]

This replaces the following pattern with a simple assertThrows(...):

try {
   ...
   fail(...)
} catch (Exception e) {
}

[github-actions]

Test Results

   546 files  + 7     546 suites  +7   26m 21s ⏱️ - 5m 43s
 4 425 tests +54   4 408 ✅ +52   17 💤 +3  0 ❌  - 1 
16 746 runs  +54  16 619 ✅ +52  127 💤 +3  0 ❌  - 1 

Results for commit 01eef18. ± Comparison against base commit 2e13c10.

[akurtakov]

Thank you!