Don't throw and exception when raise on error is set to false

[Tasty213]

As raised in #276 and in compliance with the specification make it so that running the detect method on a detector with raise_on_error set to false doesn't throw an exception if it can't find any GCP resources.

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[aabmass]

@Tasty213 can you sign the CLA?

[Tasty213]

I think I've already done so? The check shows as passed

[Tasty213]

fixed the linter error

[aabmass]

/gcbrun

[Tasty213]

Could've sworn the linter passed locally

[aabmass]

Could've sworn the linter passed locally

Could be some weird flake in the CI setup. Lmk if you have trouble getting it to pass in CI and I can try to fix it

[Tasty213]

Figured out what was wrong with my local testing, I use Windows and have git to checkout CRLF and commit LF, so when I ran the linter locally every single file threw a warning as it was in the 'wrong' line ending style giving pylint unexpected-line-ending-format. I've set pycharm to force everything in the project to LF but now git reckons I've changed every file (until I try and stage and it realises I haven't).

Either way this should now pass the lint step.

[aabmass]

/gcbrun

[aabmass]

Thank you for contributing!