[mlir][Linalg] NFC - Drop AliasInfo::existsNonDominatingRead

The case where a non-dominating read can be found is captured by slightly generalizing `AliasInfo::wouldCreaateReadAfterWriteInterference`.

This simplification will make it easier to implement bufferization across function call.

APIs are also simplified were possible.

Differential revision: https://reviews.llvm.org/D104845