slither fails with no detectors results and sarif output

[sveitser]

Describe the issue:

Running for example

slither --exclude-informational tests/test_node_modules/node_modules/@openzeppelin/contracts/utils/math/Math.sol --sarif slither.sarif

Leads to a crash

tests/test_node_modules/node_modules/@openzeppelin/contracts/utils/math/Math.sol analyzed (1 contracts with 61 detectors), 0 result(s) found
Traceback (most recent call last):
  File "/home/lulu/r/crytic/slither/venv/bin/slither", line 33, in <module>
    sys.exit(load_entry_point('slither-analyzer', 'console_scripts', 'slither')())
  File "/home/lulu/r/crytic/slither/slither/__main__.py", line 643, in main
    main_impl(all_detector_classes=detectors, all_printer_classes=printers)
  File "/home/lulu/r/crytic/slither/slither/__main__.py", line 831, in main_impl
    output_to_sarif(
  File "/home/lulu/r/crytic/slither/slither/utils/output.py", line 163, in output_to_sarif
    for detector in results["detectors"]:
KeyError: 'detectors'

The "detectors" key is missing because it's not added if empty:

slither/slither/__main__.py

Lines 769 to 770 in 168e962

	if results_detectors and "detectors" in args.json_types:
	json_results["detectors"] = results_detectors

Code example to reproduce the issue:

slither --exclude-informational tests/test_node_modules/node_modules/@openzeppelin/contracts/utils/math/Math.sol --sarif slither.sarif

Version:

0.8.3 or fba37f2

Relevant log output:

No response