test: enable --allow-uncaught in mocha runs (#7575)

test: enable --allow-uncaught in mocha runs

Add --allow-uncaught to mocha-based test scripts in package.json so
uncaught errors are treated as fatal instead of being absorbed by mocha.

Update the direct mocha invocation in platform.yml to match script behavior
for CI jobs that do not go through npm/yarn test scripts.

refactor(test): centralize mocha allow-uncaught flag

Configure allowUncaught in .mocharc.js and remove duplicated
--allow-uncaught flags from test scripts and workflow invocation.
This keeps mocha behavior consistent while reducing script noise.

Co-authored-by: Cursor <cursoragent@cursor.com>

Merge branch 'master' into watson/mocha-abort-on-uncaught

Co-authored-by: thomas.watson <thomas.watson@datadoghq.com>

Author: watson

.mocharc.js

@@ -1,6 +1,7 @@
 'use strict'
 
 module.exports = {
+  allowUncaught: true,
   color: true,
   exit: true,
   timeout: 5000,