Remove deprecated missingResolverDataFetcher option in 15.0.0 #846

SchemaParserOptions.missingResolverDataFetcher has been deprecated since 13.0.4 (8b27ed6, March 2023) in favour of missingResolverDataFetcherProvider. We should remove it in the next major release (15.0.0).

It's a breaking change, so it can't go into a 14.x release: SchemaParserOptions.Builder.missingResolverDataFetcher(...) and the SchemaParserOptions.missingResolverDataFetcher property are both public.

What to remove

• missingResolverDataFetcher from the SchemaParserOptions constructor and the builder
• the fallback to it in MissingFieldResolver and the null check in FieldResolverScanner.missingFieldResolver
• the test in MissingFieldResolverTest that covers the deprecated option

Migration

// before
.missingResolverDataFetcher(fetcher)
// after
.missingResolverDataFetcherProvider { _, _ -> fetcher }

Other breaking cleanups for the same release

• the environment.getContext() fallback for custom context classes in MethodFieldResolver (already has a "remove in next major" TODO)
• the getContext() fallback for a CoroutineScope passed as the legacy context object in Utils.coroutineScope(); it now logs a warning and should be read from GraphQLContext instead