S3-compatibility. Update documentation that feature has not be planned anymore

[AlexeyALeonov]

In the "ListObjects" entry on https://github.com/storj/gateway-st/blob/main/docs/s3-compatibility.md#listobjects, the "planned support" column says "Planned full. See storj/roadmap#20 (https://github.com/storj/roadmap/issues/20) ". However, the storj/roadmap#20 (https://github.com/storj/roadmap/issues/20) issue is closed as saying Storj is "not actively working on any S3 compatibility items" (https://github.com/storj/roadmap/issues/20#issuecomment-1181126223) .

It seems that the documentation is inconsistent.