{.async: (raises).} for relay/utils.nim

[etan-status]

Annotate relay/utils module with {.async: (raises).}. These build on top of writeLp and can be updated independently of the rest of libp2p.

[codecov]

Codecov Report

Attention: Patch coverage is 95.65217% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 82.77%. Comparing base (ae13a0d) to head (a7fa2dc).

Additional details and impacted files

@@             Coverage Diff              @@
##           unstable    #1058      +/-   ##
============================================
- Coverage     82.79%   82.77%   -0.03%     
============================================
  Files            91       91              
  Lines         15749    15753       +4     
============================================
- Hits          13040    13039       -1     
- Misses         2709     2714       +5     

Files	Coverage Δ
libp2p/protocols/connectivity/relay/utils.nim	94.44% <95.65%> (-2.11%)	⬇️

... and 3 files with indirect coverage changes

[etan-status]

• Async exception tracking #962