test: correct native-suite-count to 37

The canonical suite count drifted from the actual test/test_*/ directory count
upstream on develop: #10669 added two suites but bumped the count by one, and
#11037 added test_xmodem without bumping it at all - leaving native-suite-count
at 35 against 37 real suites, which run-tests.sh reports as AMBER. Correct it to 37.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: NomDeTom

test/native-suite-count

@@ -1 +1 @@
-35
+37