GraphQL Playground configuration breaks BC

[bkosun]

API Platform version(s) affected: ≥ 4.1.18

Description
The GraphQL Playground IDE was deprecated in version 3.1.0 (#5309) and removed in 4.1.18 (#7204).

Versions 3.1.0 - 4.1.17 emit the following warning:

Since api-platform/core 3.1: GraphQL Playground is deprecated and will be removed in API Platform 4.0. Only GraphiQL will be available in the future. Set api_platform.graphql.graphql_playground to false in the configuration to remove this deprecation.

This warning can be suppressed as follows:

graphql:
   graphql_playground: false

or

graphql_playground:
    enabled: false

However, in version 4.1.18 this configuration produces an error:

Unrecognized option "graphql_playground" under "api_platform.graphql". Available options are "collection", "default_ide", "enabled", "graphiql", "introspection", "max_query_complexity", "max_query_depth", "nesting_separator".

To ensure backward compatibility, a patch was applied (#7274), however, when trying to update version ≤ 4.1.18 to 4.1.19 - 4.2.17, an error will occur:

graphql:
    graphql_playground: false

Invalid type for path "api_platform.graphql.graphql_playground". Expected "array", but got "bool"

or

graphql_playground:
    enabled: false

Unrecognized option "enabled" under "api_platform.graphql.graphql_playground". Available options are "".

How to reproduce
Set the graphql_playground option in versions ≤ 4.1.18 and update the package to 4.1.19 - 4.2.17.

Possible Solution
It seems the graphql_playground option should be allowed to be used even if it has no effect, to ensure backward compatibility and safe package updates.