infra: don't create already existing releases #71
Description
Context: https://github.com/near/borsh-rs/runs/4950355234?check_suite_focus=true
cargo-workspaces should detect and skip existing tags (see https://github.com/miraclx/cargo-workspaces/blob/b2d49b9e575e29fd2395352e4d0df47def025039/cargo-workspaces/src/utils/git.rs#L327-L339) but it seems https://github.com/actions/checkout doesn't pull tags by default.
Investigating a possible solution: actions/checkout#400 (comment)
https://github.com/rust-analyzer/rust-analyzer/blob/2cb85c14b622002767c66881c6a316a94e0f0be4/.github/workflows/publish.yml#L19-L20