[emulator] Drop false claim that tests run in the main suite

The README stated tests/python/test_emulator.py loads this module so the tests
run as part of the main Binary Ninja test suite, but that file does not exist and
nothing under tests/ references the emulator. Remove the inaccurate paragraph.

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

Author: xusheng6

plugins/emulator/README.md

@@ -52,10 +52,6 @@ PYTHONPATH=<bn install>/python python3 -m pytest test/emulator_test.py
 PYTHONPATH=<bn install>/python python3 test/emulator_test.py
 ```
 
-Inside the Binary Ninja source tree these same tests also run as part of the main
-Binary Ninja test suite (`tests/python/test_emulator.py` loads this module), so
-`cd tests && pytest python` exercises them alongside everything else.
-
 ## Support status
 
 Only **LLIL** emulation is supported today. **MLIL and HLIL emulation are planned** for the