Update substrate to pick up peering fix

[nathanwhit]

Description of proposed changes:
Updates substrate to include the changes from paritytech/substrate#11429 in order to improve the peering situation on testnet. (The update is from gluwa/substrate@57cab2f to gluwa/substrate@973dd74)

Practical tips for PR review & merge:

• All GitHub Actions report PASS
• Newly added code/functions have unit tests
  • Coverage tools report all newly added lines as covered
  • The positive scenario is exercised
  • Negative scenarios are exercised, e.g. assert on all possible errors
  • Assert on events triggered if applicable
  • Assert on changes made to storage if applicable
• Modified behavior/functions - try to make sure above test items are covered
• Integration tests are added if applicable/needed

[codecov-commenter]

Codecov Report

Merging #249 (850c8fd) into testnet (5569ce8) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff            @@
##           testnet     #249   +/-   ##
========================================
  Coverage    56.73%   56.73%           
========================================
  Files           33       33           
  Lines         5485     5485           
========================================
  Hits          3112     3112           
  Misses        2373     2373           

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[atodorov]

@nathanwhit don't we need the same patch/PR opened against dev as well ? I think we do.