Update EIP-8079: Fix grammar errors in EIP-8079

[fr0mano]

Fixed three grammar errors in EIP-8079:

1. Line 19: "each other efforts" → "each other's efforts" (possessive form required)
2. Line 124: "constrained their behaviour" → "constrain their behaviour" (infinitive after "to define...and")
3. Line 130: "they already benefits from" → "they already benefit from" (plural subject "projects" requires plural verb)

[eth-bot]

File EIPS/eip-8079.md

Requires 1 more reviewers from @justindrake, @lucadonnoh