fix(ls): temporary quick fix false positive for schema reference

[frantuma]

@char0n

Refs swagger-api/swagger-editor#3722
Refs swagger-api/swagger-editor#4026

This is a temporary quick fix to avoid false positives in OAS 3.0.x anyOf, oneOf and allOf constructs, until the "real" underlying issue in schema parsing in OAS 3.0 spec is resolved (e.g. adding referenced-element meta or other solution)

This fix would cause a reference to a non schema not to be considered as error for OAS 3.0, but that missing negative is IMO less annoying for users as the current false positive

[char0n]

I'll see if I can add referenced-element to the meta during tomorrow morning. The code is there, so it should be adding referenced-element when expected, but there must be a bug, which is preventing

[char0n]

@frantuma addressed missing meta in OpenAPI 3.0.x namespace: #2987

Can you rebase this PR against main branch and see it works as expected?

[frantuma]

replaced by #2987 which fixes swagger-api/swagger-editor#3722 and swagger-api/swagger-editor#4026