Should ObjectMapper throw IOException?

[mikehearn]

Issue description

I was a bit surprised to discover that ObjectMapper.writeValueAsString throws IOException even though it's not doing IO. There is no description of when this can be thrown or why. Perhaps there should be a tighter / clearer exception type introduced in Micronaut 5?

[yawkat]

The method can still throw a SerdeException (which extends IOException), and any IOException that the encoder throws (format dependent, e.g. field size limits), so I don't think it can be more narrow.