fix(gw): negative entity-bytes beyond file size

[lidel]

This PR aims to do end-to-end smoke-test and validation of upstream fixes:

• Run tests from https://github.com/ipfs/gateway-conformance/pull/190
• Against fix from https://github.com/ipfs/boxo/pull/523

TODO

• [x] make gateway-conformance test on this PR greeen
  • done, small fixes of top of Hannah's changes: https://github.com/ipfs/gateway-conformance/pull/190/commits/7ed58d142a6a8295777f5a6a5bd4f8e68c179355, https://github.com/ipfs/boxo/pull/523/commits/c3931cfaf4b36ec0e5def1499177a2b3c3bf6478
• [x] switch this PR to gateway-conformance release with https://github.com/ipfs/gateway-conformance/pull/190
• [x] switch this PR to boxo main branch commit with https://github.com/ipfs/boxo/pull/523
• [x] PR ipfs/specs with one sentence that says entity-bytes range overflows in both directions SHOULD be ignored / truncated: done https://github.com/ipfs/specs/pull/460