Ignore reveal_type errors when parsing Pyre output

[yangdanny97]

Pyre generates diagnostics for reveal_type like any other type error, since it doesn't distinguish between errors and warnings in the output.

The mypy and pyright reveal_type diagnostics are prefixed with note and info, which get filtered out when parsing the output. This PR updates Pyre's output parsing to ignore reveal_type errors. They'll still show up in the output, but they will no longer cause "unexpected error" conformance mismatches that need to be manually checked.