Player: update alliance cache immediately in joinAlliance

[hemberger]

This fixes an issue where the alliance roster does not immediately update when a player clicks the "Join" button on the Alliance Roster page.

[codecov]

Codecov Report

❌ Patch coverage is 0% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 35.62%. Comparing base (6db4d94) to head (3dd7e15).

Files with missing lines	Patch %	Lines
src/lib/Smr/Player.php	0.00%	2 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff              @@
##               main    #2432      +/-   ##
============================================
- Coverage     35.63%   35.62%   -0.01%     
- Complexity     4313     4314       +1     
============================================
  Files           132      132              
  Lines         12896    12898       +2     
============================================
  Hits           4595     4595              
- Misses         8301     8303       +2     

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