[mlir][linalg] Fix EraseIdentityLinalgOp on fill-like ops (#130000)
Adds a check to make sure that the linalg op is safe to erase by
ensuring that the `linalg.yield` is yielding one of the linalg op's
block args. This check already exists for linalg ops with pure tensor
semantics.
Closes https://github.com/llvm/llvm-project/issues/129414
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Signed-off-by: Ian Wood <ianwood2024@u.northwestern.edu>