Update testnet to 5.1.1

[codecov[bot]]

Codecov Report

Merging #1356 (4748c58) into testnet (af68616) will decrease coverage by 0.00%. The diff coverage is n/a.

@@             Coverage Diff             @@
##           testnet    #1356      +/-   ##
===========================================
- Coverage    44.01%   44.00%   -0.01%     
===========================================
  Files          141      141              
  Lines        29952    29952              
===========================================
- Hits         13182    13181       -1     
- Misses       16770    16771       +1     

Impacted Files	Coverage Δ
pallets/runtime/develop/src/runtime.rs	41.73% <ø> (ø)
primitives/src/identity_claim.rs	63.51% <0.00%> (-1.36%)	:arrow_down:
pallets/identity/src/keys.rs	80.40% <0.00%> (-0.16%)	:arrow_down:
pallets/balances/src/lib.rs	57.23% <0.00%> (+0.13%)	:arrow_up: