#docs: Update Bytes, immutables performance report

[sebastiantf]

Describe the bug
Docs in https://github.com/messari/subgraphs/blob/master/docs/PERFORMANCE.md#results-3 reports that Bytes as ids and immutables did not help improve performance. But following the thread on graphprotocol/graph-node#3534, it seems this is not the case, anymore? Docs could be updated appropriately to avoid misleading future readers, if this was indeed resolved

Apologies for marking this as a bug. Couldn't find an appropriate type to report this

Reproduction
N/A

Expected behavior
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Screenshots
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Additional context
Nil

[steegecs]

Docs have been updated. Thanks for bringing this to our attention! #2173